34 posts · 15,961 views
The selected few contributors are from, and based in, three different continents (Asia, South America, and Europe) and have worked/studied/lived in four different continents. They have different backgrounds and have been educated in certain universities, in different disciplines, and are currently employed in different facets. Some have engaged/or are current working on research projects concerned with the environment. However, they all are united in their concern for the environment.
As you sit in the rush hour queues, pity the poor guy or girl directing the traffic, and imagine the fumes they are breathing in. In Brazil, with rapidly expanding car ownership, but not necessarily expanding road space, this is an increasing problem.
A recent study* in the city of Santo Andre, part of the metropolitan region of Sao Paulo, focused on traffic controllers. The study focused on male, non smoking, traffic controllers who had been exposed for over 3 years. As the authors note, one criticism of the study is that it might actually underestimate health concerns, as unhealthy controllers were excluded from the test group to achieve homogeneity. Thus the subjects might be constitutively more able to adapt to air pollution, or just have healthier working practices.
The study concentrated on particles in the air (from dust, car exhaust etc) and ozone. The level of particulate matter has fallen in recent years, below the official limits of 50 and 25 ug/m3 for PM10 and PM2.5 respectively (PM 10 and 2.5 are different particle sizes), but that is still considered hazardous by many observers. Road dust accounts for about 30% of air pollution and is mainly composed of PM 10 particles, so the authors concentrated on this size in particular. Furthermore ozone levels are increasing, especially at times of high temperatures and low humidity. High ozone has been associated with cardiovascular disease.
They found that both PM10 particulates and ozone were associated with increased blood pressure, but in different ways. PM10 pollution caused a blood pressure rise almost immediately, which still remained 4 hours later, whilst the effect of ozone delayed for 2 hours of exposure, but was still apparent 5 hours later.
So, the traffic controllers are suffering measurable cardiovascular effects every day, continuing even when the pollution is removed, and in quite a stressful job. It might not end there. The so called "interior diesel" used in some cities such as Santo Andre has a lot more sulphur than the diesel distributed in the main cities (1,200 vs 500 ppm), which has been shown to cause endothelial disfunction, oxidative stress, and probably long term hypertension.
It's a dangerous job, standing in the middle of traffic, in more ways than one.
Sérgio Chiarelli P, Amador Pereira LA, Nascimento Saldiva PH, Ferreira Filho C, Bueno Garcia ML, Ferreira Braga AL, & Conceição Martins L (2011). The association between air pollution and blood pressure in traffic controllers in Santo André, São Paulo, Brazil. Environmental research, 111 (5), 650-5 PMID: 21570068
*P.S. Chiarellietal et al 2011. The association between air pollution and blood pressure in traffic controllers in SantoAndre, Sao Paulo, Brazil Environmental Research 111 650–655
... Read more »
Sérgio Chiarelli P, Amador Pereira LA, Nascimento Saldiva PH, Ferreira Filho C, Bueno Garcia ML, Ferreira Braga AL, & Conceição Martins L. (2011) The association between air pollution and blood pressure in traffic controllers in Santo André, São Paulo, Brazil. Environmental research, 111(5), 650-5. PMID: 21570068
Growing up in Southern India, we cultivated several vegetables and spices in our backyard, one of which was turmeric. Turmeric (Curcuma longa) belongs to the same family as ginger. It is rhizomatous herb and normally pieces of the rhizome are planted in the rainy months of July. In our hands, the plants did not require much care at all. No artificial fertilizers were used nor wwere the plants watered but only left to the mercy of nature. But our part of South India is blessed with rains anyway, at least then, before the global warming and stuff but that’s another story. The rhizomes were harvested in the following summer. One signal that it was time for harvest was the death of the leaves. Once this occurred, the root tubers were all plucked out from the soil. This often coincided with the latter half of the summer vacations and was a joyous occasion for us when we were children. The tubers were then washed in water to remove the soil. By the time the mud was washed off our little palms would all be yellow. Imagine our delight when our hands turned read when we tried to wash it away with soap (Turmeric is a PH indicator turning from yellow to red in alkaline conditions). The tubers were then sun dried and pulverized to be used for culinary purposes. Turmeric occupies a lofty place in Indian culture, well almost like gold. In fact nearly most of South Indian dishes use it as a seasoning. In Ayurveda, it is associated with a manifold health benefits. Apart from using turmeric powder to spice dishes, the fresh root tubers are ground and used as masques on the skin which issupposed to prevented sun induced damage and blemishes. It also plays an important role in auspicious ceremonies like weddings. In many sections of the Indian society the prospective bride and bridegroom have ritual baths with turmeric due to its edifying propertiesFor the last decade or so, turmeric has moved from the spice cupboards in Indian kitchens to the laboratory benches where researchers are investigating the overwhelming evidence of its' beneficial effects. It is estimated that turmeric has about 100 constituents. 5% of the rhizome comprises of essential oils and 5% curcumin, the latter is the best studied active substance. Curcumin is identified as responsible for most of the biological effects of turmeric although whether turmeric as a whole or curcumin is isolation is most effective is debated. Some believe that turmeric as a whole is superior than curcumin for some conditions (http://www.drweil.com/drw/u/QAA400915/Curcumin-or-Turmeric.html). Indeed, most research activity has centred around curcumin in isolation. Imagine the complexity if the labs were to investigate the individual compounds that make up turmeric. Turmeric can rightly be called ‘ the mother of all spices’ . In fact evidence indicates that it is anti inflammatory, anti carcinogenic and anti diabetic to name a few of its health benefits. How turmeric exerts is manifold benefits is only starting to unravel as several labs around the world are investigating the molecular mechanisms of curcumin. Limited evidence suggests that turmeric and its active compound, curcumin, are effective for rheumatoid arthritis and other inflammatory diseases such as psoriasis, inflammatory bowel disease (IBS), inflammatory eye disease and familial adenomatous polyposis. Other inflammatory diseases where turmeric might play an important role are neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, multiple sclerosis. Indeed these diseases are less common among people living in the Asian subcontinent, where people regularly consume spices. More in a futue postCheck these links that review therapeutic roles curcumin Howes MJ, Perry E. The role of phytochemicals in the treatment and prevention of dementia.World J Gastrointest Pathophysiol. 2011 Feb 15;2(1):1-14. Rajasekaran SA. Therapeutic potential of curcumin in gastrointestinal diseases. Drugs Aging. 2011 Jun 1;28(6):439-68.Wilken R, Veena MS, Wang MB. Curcumin: A review of anti-cancer properties and therapeutic activity in head and neck squamous cell carcinoma. Mol Cancer. 2011 Feb 7;10:12.Park J, Conteas CN. Anti-carcinogenic properties of curcumin on colorectal cancer. World J Gastrointest Oncol. 2010 Apr 15;2(4):169-76.Pocernich CB, Bader Lange ML, Sultana R, Butterfield DA. Nutritional Approaches to Modulate Oxidative Stress in Alzheimer's Disease. Curr Alzheimer Res. 2011 May 23. Huang J, Plass C, Gerhäuser C. Cancer Chemoprevention by Targeting the Epigenome. Curr Drug Targets. 2010 Dec 15.... Read more »
Howes MJ, & Perry E. (2011) The role of phytochemicals in the treatment and prevention of dementia. Drugs , 28(6), 439-68. PMID: 21639405
Rajasekaran SA. (2011) Therapeutic potential of curcumin in gastrointestinal diseases. World journal of gastrointestinal pathophysiology, 2(1), 1-14. PMID: 21607160
Wilken R, Veena MS, Wang MB, & Srivatsan ES. (2011) Curcumin: A review of anti-cancer properties and therapeutic activity in head and neck squamous cell carcinoma. Molecular cancer, 12. PMID: 21299897
Park J, & Conteas CN. (2010) Anti-carcinogenic properties of curcumin on colorectal cancer. World journal of gastrointestinal oncology, 2(4), 169-76. PMID: 21160593
Pocernich CB, Bader Lange ML, Sultana R, & Butterfield DA. (2011) Nutritional Approaches to Modulate Oxidative Stress in Alzheimer's Disease. Current Alzheimer research. PMID: 21605052
Huang J, Plass C, & Gerhäuser C. (2010) Cancer Chemoprevention by Targeting the Epigenome. Current drug targets. PMID: 21158707
On June 1st Dilma Rousseff, the President of Brazil, controversially gave permission for the company Norte Energia to begin building a hydroelectric dam on the Xingu river in the northern state of Para. This follows the granting of a provisional licence in January by the previous president, Lula da Silva, to begin land clearance and road construction, and years of court cases. A total of eleven cases have been filed against the project by the Federal Public Prosecutor, over various irregularities, the last being overturned in February.Artists impression of the damThe Belo Monte dam complex will in fact consist of 3 dams. The first, Pimental Dam, will be 36 metres tall, over 6 kilometres long, and will create a lake with a surface area of 129 square miles. This will supply one power station. Two canals will channel water down to another reservoir created by the Belo Monte dam, which will supply another power plant. The Belo Monte dam will be 90 metres tall but only 3.5 kilometres wide, and create a lake of 42 square miles. The whole complex is expected to cost 16 billion US$, with power cables costing a further US$ 2 billion.For good or ill this is going to affect a lot of people.AdvantagesOn the positive side, an immense amount of energy will be generated, the Belo Monte dam is the third largest hydroelectric project in the world after the Three Gorges Dam in China and the Itaipu dam between Brazil and Paraguay. Itaipu already supplies 19% of Brazil's energy needs and virtually all of Paraguay's. The planned capacity of Belo Monte is unclear, as we will see below, but it is claimed by EletroBras, the state electricity company to at least supply the state of Para (population 7.5 million). This of course is all power that would otherwise have to generated by fossil fuels or nuclear energy. Once built, the running costs will be minimal, and electricity will be provided continuously (well, again, see below) for over 50 years. It's not true that will be no carbon emissions. Studies of other Brazilian dams have found that as the water level falls and rises every year, vegetation flourishes in the tropical climate, only to be submerged and decay, releasing methane. But the amount is probably much less than an equivalent coal fired power station.The location, with a natural drop in elevation, allows the use of a relatively low wall, and thus smaller reservoir, to generate power requiring a much bigger reservoir elsewhere. Thus, the argument goes, if you are going to have a dam, this is the place to have it.Aluminium at BarcarenaApproximately 18,000 jobs will be created by the construction project, and another 25,000 indirectly, although of course most of these will cease when construction is finished. More long term will be aluminium processing plants powered by the dam, with a view to export to China. The planned Brazilian-Chinese bauxite processing plant at Barcarena, Para, will be the largest in the world. There are also existing Japanese and American plants which will be expanded. This gives Brazil a much higher value export product than simple ore.DisadvantagesThe disadvantages can be divided into social, practical and environmental.SocialFor a start over 20,000 people will be directly displaced. These people will need to be resettled. Then there are the people downstream, mainly from the Juruna and Arara tribes. As they will not be directly affected they have not been offered resettlement, but as the river is a major food supply and transport network, falling levels will possibly cause displacement anyway. This will probably be exasapated by increased levels of water borne diseases from more stagnant pools. In fact, the vast majority affected by this project will be indigenous peoples, and this has aroused a lot of resentment, and threats of violence.In contrast, an estimated 100,000 migrants from other parts of Brazil will enter the area. It is not clear what infrastructure will be in place to support them.PracticalA number of studies have cast doubt on the economic viability of the project. The ex-President of Sapesp, the Sao Paulo state water company , has claimed it will be one of the most inefficient hydroelectric power projects in Brazilian history. Mainly because of the seasonal nature of water supply via the Xingu river, so that it will be at 30% capacity or less from June to October.Actually there is a solution to that - another dam. Although the intention is vehemently denied, a further dam at Altamira up stream would create a 2,000 sq mile lake and a year round water supply, making the whole project much more viable. It would also displace another estimated 25,000 people. The long term intention to build another dam would be easier to dismiss if the turbine capacity of the planned power stations were not considerably more than the likely water flow.Another artists impressionEnvironmentalConstruction of the dam required an environmental licence from IBAMA, the Brazilian environmental agency, and this was granted in February 2010. Controversially. Two IBAMA presidents and at least two senior officials have resigned claiming undue government pressure to approve the licence. Even now, the licence is technically provisional with many requirements yet to be met before a full licence can be granted, but that is moot as a judge has ruled that work can commence without a full licence.Large amounts of forest will inevitably be lost. One concern is the loss of biodiversity as a number of species are found only within the area affected by the dam, and it is extremely unlikely they would survive the drying out and/or flooding of their habitats. This apparently includes the Plant eating piranha Ossubtus xinguense (actually it's omnivorous and will eat worms and shrimps) and the Xingu poison dart frog Allobates crombie, amongst others.What is certain is that it is not just the area under the construction that will be affected. The influx of tens of thousands of migrants will consume a huge area of forest for building of homes and roads, and then farm land to support them.Further ReadingFearnside, P. (2006). Dams in the Amazon: Belo Monte and Brazil’s Hydroelectric Development of the Xingu River Basin Environmental Management, 38 (1), 16-27 DOI: 10.1007/s00267-005-0113-6Sousa Júnior, W.C. and Reid, J. 2010. Uncertainties in Amazon hydropower development: Risk scenarios and environmental issues around the Belo Monte dam. Water Alternatives 3, 249-268... Read more »
Fearnside, P. (2006) Dams in the Amazon: Belo Monte and Brazil’s Hydroelectric Development of the Xingu River Basin. Environmental Management, 38(1), 16-27. DOI: 10.1007/s00267-005-0113-6
Earlier this week on Monday came reports from Germany that 6 people who consumed raw vegetables were killed and hundreds rendered ill . Initial investigations pointed towards consumptions of raw cucumber, lettuce and tomatoes. The fatalities were attributed to hemolytic-uremic syndrome, or HUS, from E. Coli. Since then, more people have died and the infection has spread to different parts of Europe . Cases have been reported from Sweden, Austria, Denmark, France, Netherlands, Norway, Spain, Switzerland and the United Kingdom. At the initial stages opinions about whether the strain was new differed between scientists. Scientists at the Beijing Genomic Institute called it a new "super-toxic" E. coli strain whilst the U.S. Centers for Disease Control and Prevention said that it was a known strain.Today the WHO announced that the German strain was novel and that it had never been isolated before in humans. With the death toll having risen to 18, whilst over 1000 people remain ill, German scientists are desperately trying to sequence the bacterial genome. The news from WHO also indicates that the strain had never been found in any animals which signifies that it could have come directly from the environment into humans. The scientific community is awaiting with bated breath for the results from sequencing of the genome of this deadly strain of bacteria . The sequence of this strain of E.coli might explain the differential infection pattern observed- the bacteria is mostly infecting adults, and generally women.Emergence of super-bugs are of grave concern. In April, the Lancet reported bacteria carrying a gene that confers resistance to a major class of antibiotics identified in samples of drinking water and sewage effluents from New Delhi. This gene blaNDM-1 encodes the enzyme New Delhi metallo-β-lactamase 1 (NDM-1). Bacteria can pass genes easily through plasmids. The enzyme blocks the activity of a range of antibiotics. NDM-1-positive strains of both species have previously been found in hospitals in India and Pakistan and have already been seen in the United Kingdom and elsewhere in patients, some of whom had previously been in hospitals in the Indian subcontinent.The problem with virulent bacteria as with most infectious agents is that it is hard to be confined. As of now, the source of the German E.coli strain has not been pin pointed. With bacterial outbreaks such as this there is nothing called a ‘local problem’ but a ‘global problem’ and combating it requires a concerted effort where the blame game doesn’t help much.References:German E. coli outbreak caused by previously unknown strain (Nature, June 2nd, 2011)World health officials scramble to stem deadly E. coli outbreak (CNN, June 2nd, 2011)EHEC outbreak: Rare strain of E. coli unknown in previous outbreaks (WHO, June 2nd, 2011)Kumarasamy KK, Toleman MA, Walsh TR, Bagaria J, Butt F, Balakrishnan R, Chaudhary U, Doumith M, Giske CG, Irfan S, Krishnan P, Kumar AV, Maharjan S, Mushtaq S, Noorie T, Paterson DL, Pearson A, Perry C, Pike R, Rao B, Ray U, Sarma JB, Sharma M, Sheridan E, Thirunarayan MA, Turton J, Upadhyay S, Warner M, Welfare W, Livermore DM, & Woodford N (2010). Emergence of a new antibiotic resistance mechanism in India, Pakistan, and the UK: a molecular, biological, and epidemiological study. The Lancet infectious diseases, 10 (9), 597-602 PMID: 20705517Poirel L, Hombrouck-Alet C, Freneaux C, Bernabeu S, & Nordmann P (2010). Global spread of New Delhi metallo-β-lactamase 1. The Lancet infectious diseases, 10 (12) PMID: 21109172... Read more »
Kumarasamy KK, Toleman MA, Walsh TR, Bagaria J, Butt F, Balakrishnan R, Chaudhary U, Doumith M, Giske CG, Irfan S.... (2010) Emergence of a new antibiotic resistance mechanism in India, Pakistan, and the UK: a molecular, biological, and epidemiological study. The Lancet infectious diseases, 10(9), 597-602. PMID: 20705517
Modern cities generate huge amounts of rubbish, and disposing of this is one of the most pressing environmental problems. One can bury it of course, or burn it in incinerators, or just dump it in a big pile just outside the city. This is the approach chosen for the Jardim Gramacho in Rio, Brazil, one of the worlds largest rubbish dumps, which is the subject of the Oscar nominated film, Waste Land.*Seventy percent of Rio's rubbish arrives at Jardim Gramacho, which is an astonishing 7,000 tons every day. In a rich country with few people, trash can be passed through automated factories which remove the most valuable materials for recycling. Brazil is a not-so-rich country with a lot of people, but recycling still takes place, on a massive scale. Thousands of scavengers ("catedores") clamber over the rubbish very day - an estimated 3,000 people, supporting 13,000 men women and children. About 200 tons of material is recycled daily, 50% plastic, 21% metal and 16% paper, though metal is preferred as the most vulnerable.The catedores, incidentally, don't necessarily conform to the expected stereotype. A survey in 2004** found 90% could read and write, and 79% own their own homes. The catedores are also reported as feeling a certain amount of pride in their efforts, contrasting with other job options such as drug trafficking or prostitution.Well so far so good, the system does generate meaningful employment and recycling is a good thing, but obviously there is a price.In the 2004 survey, although 70% used gloves only 0.9 use masks. Over 20% reported "colds or flu" in the previous 6 months and 10% had respiratory problems, whilst 45% had had conjunctivitis at some time in their past. There is also the ever present risk of cuts from glass, falling objects and burns, as well as bites from the mosquitoes which thrive in the marshes nearby, with 23% having had dengue fever. Interestingly, only 13% of those interviewed actually regarded their work as responsible for these problems, as opposed to their life in general. They may have had a point. Collecting rubbish will never make you rich, only 50% in 2004 lived in homes connected to the sewage network and ironically, about a third have no rubbish collection at home and have to burn rubbish or dump it in local waterways.One last point. Several cities such as Salvador and Recife, in northern Brazil, dump their rubbish near the airport, a text book example of an idea that "seemed a good idea at the time". After all nobody wants to live right next to a busy airport. Unfortunately, whilst people won't, vultures will. Black vultures are flourishing on the easily available food, and birds and planes do not mix. Bird strikes have more than doubled in Brazil in the past decade, and about half the cases involve vultures. Whilst a jet airliner might shrug off a hit from a sparrow, vultures are big weighing up to 2.5 kg and at least two two planes have been forced to make emergency landing after pilots were injured by vultures crashing into their windscreens. So far there have been no fatalities, but the potential is there and relocating or even killing the vultures has had limited success.As Wagner Fischer, coordinator of the wildlife management department at IBAMA, the Brazilian federal environmental oversight agency, is quoted as saying***, “What if you have a bunch of house flies in your home?, is it better to kill or relocate the flies or clean your house?”* The film incidentally follows artist Vik Muniz creating art from recycled materials, in collaboration with various catadores (hunters). It's a tribute to Muniz's talent that he has generated a very successful career from such unlikely material, including even the title sequence of the recent hugely popular Brazilian soap, Passione.** Porto, M, Junca, D, Goncalves, R Filhote, M. (2004). Garbage, work, and health: a case study of garbage pickers at the metropolitan landfill in Rio de Janeiro, Brazil. Cad. Saúde Pública [online]. vol.20, n.6, pp. 1503-1514. ISSN 0102-311X. doi: 10.1590/S0102-311X2004000600007.http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0102-311X2004000600007&lng=en&nrm=iso&tlng=en*** http://www.brazilmax.com/news.cfm/tborigem/tt_prstuff/id/2Porto MF, Juncá DC, Gonçalves Rde S, & Filhote MI (2004). [Garbage, work, and health: a case study of garbage pickers at the metropolitan landfill in Rio de Janeiro, Brazil]. Cadernos de saude publica / Ministerio da Saude, Fundacao Oswaldo Cruz, Escola Nacional de Saude Publica, 20 (6), 1503-14 PMID: 15608851... Read more »
Porto MF, Juncá DC, Gonçalves Rde S, & Filhote MI. (2004) [Garbage, work, and health: a case study of garbage pickers at the metropolitan landfill in Rio de Janeiro, Brazil]. Cadernos de saude publica / Ministerio da Saude, Fundacao Oswaldo Cruz, Escola Nacional de Saude Publica, 20(6), 1503-14. PMID: 15608851
Climate change has been resulting in quite a many detrimental manifestations which tend to have a domino effect: fluctuations in temperature and precipitation (resulting in climate variability), as well as extreme manifestations such as drought, storms, rise in sea levels, and frequent severe weather events.Consider the research by Grinsted et al (2009) who used a ‘physically plausible four parameter linear response equation’ to relate nearly 2,000 years of global temperatures and sea level. Assuming that this relationship holds from 200 to 2100 AD, IPCC’s temperature scenarios and reconstructed past sea level scenarios were used to visualise future sea level scenarios. The result suggests that climate change will lead to a 0.9-1.3 m change in sea level between 2090-2099. This bodes a certain flooding of low lying coastal regions and islands. Island countries such as Maldives would practically cease to exist. Whilst countries such as Bangladesh may not face such obliteration, such a sea level rise would flood 1/3rd of the country, displacing millions of humans and severely affecting agriculture, irrigation, and livestock.Climate change also has a perceptible impact on human morbidity and mortality (Patz et al, 2005). Climate fluctuations have been linked to diseases and ailments- the evident effects of heat/cold (which, for instance, follows a U-shaped dose-response function with increased mortality in the extreme heat and cold), traumatic physical and mental ailments, and even cardiovascular and respiratory illnesses. This even results in altered transmission of infectious diseases (for instance, changes in temperature has been associated with salmonellosis in Europe and cholera in the ‘American south-west’; whilst, changes in rainfall has been associated with Rift valley fever in East Africa, and Hantavirus pulmonary syndrome and cholera in the American south-west and Bangladesh). When one factors in the effects of climate change on air pollution and the greater ecosystem, the result is quite chaotic. If the future projections of climate change are plausible, then it is likely that these health risks may rise significantly. The ‘potentially vulnerable’ regions includes the temperate latitudes (which may warm disproportionately), and the regions in and around the Pacific and Indian oceans (substantial rainfall variability).But even though the economic North/developed countries are responsible for most of the greenhouse gas emissions, the damaging effects of their actions are most perceived in the poor countries of the South which has (as of yet) contributed least towards the GHG emissions. References:Patz, J., Campbell-Lendrum, D., Holloway, T., & Foley, J. (2005). Impact of regional climate change on human health Nature, 438 (7066), 310-317 DOI: 10.1038/nature04188Grinsted, A., Moore, J., & Jevrejeva, S. (2009). Reconstructing sea level from paleo and projected temperatures 200 to 2100 ad Climate Dynamics, 34 (4), 461-472 DOI: 10.1007/s00382-008-0507-2... Read more »
Grinsted, A., Moore, J., & Jevrejeva, S. (2009) Reconstructing sea level from paleo and projected temperatures 200 to 2100 ad. Climate Dynamics, 34(4), 461-472. DOI: 10.1007/s00382-008-0507-2
The recent oil spill in the Gulf of Mexico released, as we have all seen on tv, a lot of oil. Quite how much is a "lot" is a bit of a guess, but roughly 4.9 million barrels, or 784 million litres*. What actually happened to this oil was reviewed recently in an article in Science (Kerr 2010). Only about 0.1% was recovered from beaches and marshes (that´s still an awful lot of oil!). About 17% was siphoned away at the well head, 5% burned off at the surface, and only 3% skimmed off by booms, despite a lot of effort and money spent. And the other 75%? It's, er, disappeared.So where did this oil go? Some evaporated, but with luck most of it was eaten.Oil is energy, that's why we use it in our cars and power stations. And energy means food. There are actually quite a few bacteria that digest and breakdown crude oil, and these are massively important in the recovery of the ocean from disasters like this. They work as a consortium, each concentrating on a particular fraction of the oil, and as one hydrocarbon is degraded to another, other bacteria take over. The first, and so in many ways the most important, are Alcanivorax species (Vila et al 2010). These are found in tiny quantities in unpolluted waters, but their numbers rocket when in the presence of linear and branched alkanes, common in crude oil. In fact they are so specialised for this type of hydrocarbon that without long chain alkenes they grow very poorly, but by then their job is done. Now other species such as Roseovarius and Marinobacter take over.This breakdown was helped by the massive release of chemical dispersants at the oil head, 1.1 million gallons (Kintisch 2010). These are similar to the detergent in your kitchen, breaking down lumps of oil into tiny droplets, which are "dispersed" and can be attacked much more efficiently by bacteria. This was very controversial, as dispersants are pretty toxic and an immense quantity was involved. Still, it seemed to work, and much of the oil was broken down into 1-10 micrometer droplets. In fact, it started to raise fears that it was working TOO well, a microbial explosion depriving the ocean floor of oxygen and creating a huge dead zone. But this seems not to have happened, and in fact so far the prognosis is good.We´re not out of the woods yet, the oil could yet turn up in unwanted places, and chemical damage by detergents might yet, for instance, devastate the local tuna population. But there have been lessons learnt for next time - and there will be a next time.Kerr RA (2010). Gulf Oil Spill. A lot of oil on the loose, not so much to be found. Science (New York, N.Y.), 329 (5993), 734-5 PMID: 20705818http://www.sciencemag.org/cgi/content/full/sci;329/5993/734?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=oil biodegradation&searchid=1&FIRSTINDEX=0&sortspec=date&resourcetype=HWCITKintisch E (2010). Gulf Oil Spill. An audacious decision in crisis gets cautious praise. Science (New York, N.Y.), 329 (5993), 735-6 PMID: 20705819http://www.sciencemag.org/cgi/content/full/329/5993/735Vila, J., Nieto, J., Mertens, J., Springael, D., & Grifoll, M. (2010). Microbial community structure of a heavy fuel oil-degrading marine consortium: linking microbial dynamics with polycyclic aromatic hydrocarbon utilization FEMS Microbiology Ecology DOI: 10.1111/j.1574-6941.2010.00902.x* the oil "barrel" is actually based on a type of old English wine barrel or "teirce" holding 35 gallons.... Read more »
Kerr RA. (2010) Gulf Oil Spill. A lot of oil on the loose, not so much to be found. Science (New York, N.Y.), 329(5993), 734-5. PMID: 20705818
Kintisch E. (2010) Gulf Oil Spill. An audacious decision in crisis gets cautious praise. Science (New York, N.Y.), 329(5993), 735-6. PMID: 20705819
Vila, J., Nieto, J., Mertens, J., Springael, D., & Grifoll, M. (2010) Microbial community structure of a heavy fuel oil-degrading marine consortium: linking microbial dynamics with polycyclic aromatic hydrocarbon utilization. FEMS Microbiology Ecology. DOI: 10.1111/j.1574-6941.2010.00902.x
The way by which living organisms in our planet are intricately connected is beautiful beyond comprehension. Like pieces in a puzzle they all fit together with the activities of each organism however trivial it may appear to be, affecting the existance of others. We will never fully understand this marvel, but a noteworthy example is the elegant finding by Lavery et al published in the Proceedings of the Royal Society (Biological Sciences)- Iron defecation by sperm whales stimulates carbon export in the Southern Oceanhttp://rspb.royalsocietypublishing.org/content/early/2010/06/14/rspb.2010.0863.fullThe authors provide compelling evidence on the role that sperm whales (Physeter macrocephalus) in the Southern ocean play in promoting nutrient cycling and their function as carbon sinks. Lavery et al show that the whales consume prey at the depths of the ocean but expel the waste about 50 tonnes of iron iron-rich liquid buoyant faecal matter each year into the photic zone near ocean surface. The researchers estimate that if three quarters of this iron persisted there, 36 tonnes of iron to the photic zone per year are contributed by the activities of the Southern Ocean sperm whale alone. Iron is a nutrient essential for the growth of phytoplanton which live in the photic zone. Consequentially, iron enrichment causes phytoplankton blooms resulting in carbon export during photosythesis. Additionally, phytoplankton are consumed by zooplankton. The zooplankton are consumed by squids that form the food of the whales, thereby creating a positive feedback loop. Thus this toilette behaviour of the whale benefits it as well! The researchers estimate that sperm whales stimulated the export of 4 × 105 tonnes of carbon per year to the deep ocean whilst respiring 2 × 105 tonnes of carbon per year thereby mopping up carbon. This paper also highlights the issue as to how industrial whaling leading to large scale depletion of sperm whales might have impeded the ability of the Southern Ocean to act as a carbon sink. Lavery, T., Roudnew, B., Gill, P., Seymour, J., Seuront, L., Johnson, G., Mitchell, J., & Smetacek, V. (2010). Iron defecation by sperm whales stimulates carbon export in the Southern Ocean Proceedings of the Royal Society B: Biological Sciences DOI: 10.1098/rspb.2010.0863... Read more »
Lavery, T., Roudnew, B., Gill, P., Seymour, J., Seuront, L., Johnson, G., Mitchell, J., & Smetacek, V. (2010) Iron defecation by sperm whales stimulates carbon export in the Southern Ocean. Proceedings of the Royal Society B: Biological Sciences. DOI: 10.1098/rspb.2010.0863
A new study interestingly implies that human activities may not always be bad for biodiversity. Long before the colonizers arrived in South America, indigenous farmers, belonging to the Arauquinoid cultures, had already interfered with the Amazonian biodiversity. Their novel agricultural engineering methods had changed the savannah ecosystem, resulting in increased biodiversity. Thus states the solid paper, on 'Pre-Columbian agricultural landscapes, ecosystem engineers, and self-organized patchiness in Amazonia', published in Proceedings of the National Academy of Sciences (online before print, April 12th 2010), by Doyle McKey (Université de Montpellier II, France), Stéphen Rostain, José Iriarte, Bruno Glaser, Jago Jonathan Birk, Irene Holst, and Delphine Renard. The savannahs of coastal Guyana tend to flood during the rains and are dry during the summer. However, strange complexes of mounds are seen in the terrain of these plains, running for 360 miles from Berbice River to Cayenne. Due to their perfect symmetry, the mounds were deduced to be man-made. The mounds drained well during the rains and floods (their drainage capacity was nine times as high as the seasonally flooded savannah). The authors deduce that these are large raised beds/fields, made out of the surrounding topsoil, for cultivating crops (a theory further substantiated by soil samples containing microfossils of maize, cassava, and squash), constructed by the pre-Columbian farmers, around 1000-700 years ago. The interesting point is that this farming was practiced in wastelands considered to be unsuitable for agriculture- a feat achieved due to their effective agricultural engineering. When these fields were abandoned, the mounds were colonised by flora and fauna, thus creating a new ecosystem. These 'ecosystem engineers' (viz., ants such as Acromyrmex octospinosus and Ectatomma brunneum, termites such as Nasutitermitinae, and earthworms) built their nests on the raised beds so that the colonies wouldn't be flooded. Their burrowing aerated it further, helping in accumulating sufficient rainfall. Moreover, the mounds were fertilised as a result of them congregating organic matter into their nests and accumulating minerals such as nitrogen, potassium, and calcium. As a result, the perennial plants on the mounds flourished and their strong roots prevented the erosion of the mound. All of these alterations initiated by humans have resulted in a higher biodiversity than seen in the normal savannahs. This study would give additional impetus to the debate over whether most of the Amazon rainforest and savannahs (commonly considered to be pristine) are sites of significant human occupation, especially during the pre-Columbian times. The authors suggest that this agricultural system could be a model for modern farming, especially considering the beneficial ecological changes. Although this is a perfect example of a terrain modified by humans and maintained by Nature, it must be noted the increase in biodiversity was a result of 400-800 years of no/minimal human intervention. Secondly, the ‘punja’ technique of rice/paddy cultivation has a very similar methodology and is followed in parts of Kerala. link: http://www.pnas.org/content/early/2010/04/07/0908925107.abstract?sid=93317154-3ce6-43c8-9a1e-456e24272c2bMcKey D, Rostain S, Iriarte J, Glaser B, Birk JJ, Holst I, & Renard D (2010). Pre-Columbian agricultural landscapes, ecosystem engineers, and self-organized patchiness in Amazonia. Proceedings of the National Academy of Sciences of the United States of America, 107 (17), 7823-8 PMID: 20385814... Read more »
McKey D, Rostain S, Iriarte J, Glaser B, Birk JJ, Holst I, & Renard D. (2010) Pre-Columbian agricultural landscapes, ecosystem engineers, and self-organized patchiness in Amazonia. Proceedings of the National Academy of Sciences of the United States of America, 107(17), 7823-8. PMID: 20385814
Pthalates are esters of pthalic acid that are commonly added to plastics but also are found in diverse products ranging from cosmetics to pharmaceutical pills. As could be expected, studies that monitor phthalate metabolites in human populations have shown that they are widely present. Over the years, there have been many concerns over their effect on human health notably as hormonal disrupting agents. This has led to the regulation of some phthalates in consumer products in Europe and the United States, which in some cases,have been replaced with others. Recent evidences indicate that endocrine disruption might only be a tip of the iceberg and that pthalates might have other health effects as well.It is well known that maternal exposure of pollutants make their way to the offspring and in many cases can have deleterious consequences. It appears that this dogma can also be applied to the case of the pthalates. In a study by Engel et al published in Environmental health perspectives,http://ehp03.niehs.nih.gov/article/fetchArticle.action;jsessionid=E899A81379071E8E095EF53E962F597F?articleURI=info%3Adoi%2F10.1289%2Fehp.0901470the authors questioned whether there was any association between prenatal phthalate exposure to the behavior of offspring. The study occurred in a multiethnic prenatal population enrolled in the Mount Sinai Children’s Environmental Health Study in New York City between 1998 and 2002. Urine samples of mothers during the third-trimester of pregnancy was collected and analyzed for phthalate metabolites. Subsequently, cognitive and behavioral development of the children was assessed between the ages of 4 and 9. Interestingly, the scientists found that increased concentrations of low-molecular-weight (LMW) phthalate metabolites in the mothers were associated with poorer scores on aggression, conduct problems, attention problems, and depression in the children. These results led them to conclude that behavioral domains adversely associated with prenatal exposure to LMW phthalates in this study are commonly affected in children clinically diagnosed with conduct or attention deficit hyperactivity disorders.This study and several of its predecessors, extend the known adverse effects of pthalates, which calls for increased caution. What is urgently needed are more hard core studies elucidating the toxicology of pthalates and their metabolites, that will help us understand the consequences of exposure. However, these studies will take time; the evidence at hand should motivate nations to re-evaluate their policies on pthalates and enforce strict regulations.Pthalates are esters of pthalic acid that are commonly added to plastics but also are found in diverse products ranging from cosmetics to pharmaceutical pills. As could be expected, studies that monitor phthalate metabolites in human populations have shown that they are widely present. Over the years, there have been many concerns over their effect on human health notably as hormonal disrupting agents. This has led to the regulation of some phthalates in consumer products in Europe and the United States, which in some cases,have been replaced with others. Recent evidences indicate that endocrine disruption might only be a tip of the iceberg and that pthalates might have other health effects as well.It is well known that maternal exposure of pollutants make their way to the offspring and in many cases can have deleterious consequences. It appears that this dogma can also be applied to the case of the pthalates. In a study by Engel et al published in Environmental health perspectives,http://ehp03.niehs.nih.gov/article/fetchArticle.action;jsessionid=E899A81379071E8E095EF53E962F597F?articleURI=info%3Adoi%2F10.1289%2Fehp.0901470the authors questioned whether there was any association between prenatal phthalate exposure to the behavior of offspring. The study occurred in a multiethnic prenatal population enrolled in the Mount Sinai Children’s Environmental Health Study in New York City between 1998 and 2002. Urine samples of mothers during the third-trimester of pregnancy was collected and analyzed for phthalate metabolites. Subsequently, cognitive and behavioral development of the children was assessed between the ages of 4 and 9. Interestingly, the scientists found that increased concentrations of low-molecular-weight (LMW) phthalate metabolites in the mothers were associated with poorer scores on aggression, conduct problems, attention problems, and depression in the children. These results led them to conclude that behavioral domains adversely associated with prenatal exposure to LMW phthalates in this study are commonly affected in children clinically diagnosed with conduct or attention deficit hyperactivity disorders.This study and several of its predecessors, extend the known adverse effects of pthalates, which calls for increased caution. What is urgently needed are more hard core studies elucidating the toxicology of pthalates and their metabolites, that will help us understand the consequences of exposure. However, these studies will take time; the evidence at hand should motivate nations to re-evaluate their policies on pthalates and enforce strict regulations.Engel SM, Miodovnik A, Canfield RL, Zhu C, Silva MJ, Calafat AM, & Wolff MS (2010). Prenatal phthalate exposure is associated with childhood behavior and executive functioning. Environmental health perspectives, 118 (4), 565-71 PMID: 20106747... Read more »
Engel SM, Miodovnik A, Canfield RL, Zhu C, Silva MJ, Calafat AM, & Wolff MS. (2010) Prenatal phthalate exposure is associated with childhood behavior and executive functioning. Environmental health perspectives, 118(4), 565-71. PMID: 20106747
Staunch supporters of game will find little to be pleased with the research published by Deborah Pain (of Wildfowl and Wetlands Trust, Gloucestershire) and colleagues, on Potential Hazard to Human Health from Exposure to Fragments of Lead Bullets and Shot in the Tissues of Game Animals in PLoS. The findings would also shock those who happily dig into the cooked game, seldom pondering about how much lead is ingested in the process.Lead ammunition (pellets/bullets) is often used to shoot down game. To solve their research question, Pain and her colleagues bought wild-shot game birds (grouse, mallard, partridge, pheasant, pigeon, and woodcock) from supermarkets, game dealers, shoots, and butchers. After X-raying these to determine the number of shot and shot fragments present, these were cooked using typical recipes (in wine or cider or pH-neutral cream sauce). Mimicking the traditional game eating behaviour, the visible lead fragments were manually removed.The lead concentrations in the remaining flesh were analysed. The results demonstrated that the game tissue is littered with small pieces of shot- most likely due to the ammunition disintegrating into smaller particles upon impact (and, in some cases, these fragments embed into the tissues even though the shot exits the body). Consequently, a higher level of consumption of some species may result in exceeding the current FAO/WHO’s weekly tolerable intake of lead. For instance, weekly consumption of three meals of woodcock and/or ten meals of grouse / partridge / pheasant would certainly take a 70 kilogram person over this threshold.So does the consumption of game birds (shot with lead) pose a threat to humans? – The answer is very much an ‘yes’ although this depends on the amount of game consumed. As in most studies, the vulnerable population stands a good risk. And one mustn’t overlook the impact on the food chains/webs- fauna which consume these shot game birds are inevitably affected as well. Pain DJ, Cromie RL, Newth J, Brown MJ, Crutcher E, Hardman P, Hurst L, Mateo R, Meharg AA, Moran AC, Raab A, Taggart MA, & Green RE (2010). Potential hazard to human health from exposure to fragments of lead bullets and shot in the tissues of game animals. PloS one, 5 (4) PMID: 20436670... Read more »
Pain DJ, Cromie RL, Newth J, Brown MJ, Crutcher E, Hardman P, Hurst L, Mateo R, Meharg AA, Moran AC.... (2010) Potential hazard to human health from exposure to fragments of lead bullets and shot in the tissues of game animals. PloS one, 5(4). PMID: 20436670
In this last week the Brazilian cities of Sao Paulo and Recife have experienced records levels of UV exposure. While a UV index of 6-7 is ¨high risk", and "very high risk" is 8-10, Sao Paulo was scorched with an index of 14. As the sun burns us it also beats down on the ocean surface and the algae that live there. What happens next is the subject of the CLAW hypothesis, which proposes a negative feedback loop, as follows.....Dimethylsulphide produced by phytoplankton is oxidised by bacteria to produce a sulphate aerosol on the sea surface which is a major source of cloud condensation nuclei. So more clouds, less photosynthesis and a feedback loop.That´s fine, but of course the real world is much more complicated than that. For instance, solar radiation is a double edged sword. There is increased photosynthesis, and temperature for growth, but what of UV? UV-B damages DNA in the bacteria required for DMS oxidation, killing them. It also harms the phytoplankton, who respond by producing anti-oxidants, including DMS. Together these factors increase considerably the amount of DMS in the ocean, so oceanic [DMS] and levels of UV are linked through the year. But DMS in the atmosphere and the surface waters is attacked by UV, leading to it´s photo destruction.So what happens when UV increases beyond previous levels? Does the extra production of DMS still lead to more cloud cover, a negative feedback? Or does UV kill off the oxidising bacteria and cause photodestruction in the atmosphere, leading to less cloud clover, and in turn, more UV exposure - a positive feedback loop? Oceanic acidification, as described previously by Ruth, changes water chemistry and inhibits phytoplankton growth, and so complicates matters still further.The processes mentioned here take place on such a massive scale that they affect deeply the world climate. They are incredibly complex, and rely on a interlinked series of feedback loops. What happens when feedback is disrupted has yet to be seen.For more detail see;Miles, CJ, Bell, TG, Lenton, TM 2009. Testing the relationship between the solar radiation dose and surface DMS concentrations using ub situ data. Biogeosciences, 6, 1927-1934.Miles, C., Bell, T., & Lenton, T. (2009). Testing the relationship between the solar radiation dose and surface DMS concentrations using in situ data Biogeosciences, 6 (9), 1927-1934 DOI: 10.5194/bg-6-1927-2009... Read more »
Miles, C., Bell, T., & Lenton, T. (2009) Testing the relationship between the solar radiation dose and surface DMS concentrations using in situ data. Biogeosciences, 6(9), 1927-1934. DOI: 10.5194/bg-6-1927-2009
It appears that we humans had taken oceans for granted for too long. A widely known fact is that most of what we discard makes its way to oceans. Oceans are sinks for all things including 1/3 of the carbon dioxide that has been released in the last 200 years. This has resulted in the acidification of the oceans. The science behind is that carbonic acid is formed when carbon dioxide dissolves in sea water. This raises the hydrogen ion concentration and bicarbonate ions, but limits carbonate ions. This interferes with the ability of many marine plankton to build shells. We are just beginning to understand how anthropogenic ocean acidification affects marine ecosystems and the long term consequences of this phenomenon. A report released from a team of over 100 European scientists during the Copenhagen Summit highlights this fact and alleged that marine species are being affected by the acidification of the oceans which according to the scientists are irreversible. According to the document, acidification is occurring at such a rapid pace increasing by 30% since industrial revolution and states that if CO2 emissions are not curtailed it will severely affect coral reefs, and algae. This prompts the question asking whether the acidification of oceans is uniform & universal? It seems not so, with oceans around the globe showing different degrees of acidification. North Atlantic, Pacific and Arctic seas are predicted to be affected by this phenomenon the most.Is there any cause for concern? Absolutely, The effect of acidification on plankton cannot be trivialised as they are the powerhouses and form the lower echelons of the ecosystem on which the larger vertebrates subsist.Where does the evidence for the acidification affecting plankton come from? There is convincing evidence from studies on limited species- cocolithophores and formaniferans. But there are caveats, as previous studies by different research groups on cocolithophore species had shown that not all species behave in the same way to increased carbon dioxide levels. While some species show decreased calcification , others show no change , yet another show non linear calcification and interestingly some show increased calcification. In addition, closely related organisms such as tropical and temperate sea urchins showed different responses to acidification. Even among same species, results from different laboratories showed contrasting effects. A reason for this has been attributed to different methods the labs used in mimicking acidification. Other reasons could be due to difference in experimental conditions, for example access of the species to nutrientss , temperature etc, all of which can consequently affect the way the organisms respond. Although these are valid reasons, it will be hard to convince general public of the enormity of the situation with such conflicting results. This warrants further studies.The interests in ocean acidification has been rekindled recently by the publication of a research paper from some researchers from Princeton who have given a scientific basis explaining how acidification is deleterious to plankton. It all falls on iron which is a nutrient for phytoplankton. The chemistry of iron is extremely sensitive to pH and the acidification of the sea water will alter its availability to the planktons. Shi et al showed that acidification decreased the iron uptake of phytoplankton in the laboratory. The downside of this study is that the work was done in the laboratory and field studies are needed to corroborate this.Ocean acidification is a crtical issue and we should act urgently. Often action requires concrete evidence. A unified protocol experimental protocol that is followed globally would address many of the discrepancies posed by lab based research as advocated by the researcher Victoria Fabry. But the proof of the pudding are evidences of field work. However one only hopes that those will not uncover problems that have progressed to such an extent that it is a impossible to be mitigated.Shi et al, Science 327 (2010)http://www.sciencemag.org/cgi/content/abstract/327/5966/676Fabry VJ, Science 320 (2008)http://www.sciencemag.org/cgi/content/abstract/1157130v1(PS- The topic of mismanagement of oceans was touched upon in a previous blog 'Ten Years Hence' By David BussShi D, Xu Y, Hopkinson BM, & Morel FM (2010). Effect of ocean acidification on iron availability to marine phytoplankton. Science (New York, N.Y.), 327 (5966), 676-9 PMID: 20075213Fabry, V. (2008). OCEAN SCIENCE: Marine Calcifiers in a High-CO2 Ocean Science, 320 (5879), 1020-1022 DOI: 10.1126/science.1157130... Read more »
Shi D, Xu Y, Hopkinson BM, & Morel FM. (2010) Effect of ocean acidification on iron availability to marine phytoplankton. Science (New York, N.Y.), 327(5966), 676-9. PMID: 20075213
Fabry, V. (2008) OCEAN SCIENCE: Marine Calcifiers in a High-CO2 Ocean. Science, 320(5879), 1020-1022. DOI: 10.1126/science.1157130
Tas van Ommen and Vin Morgan, of the Australian Antarctic Division, published a paper ‘Snowfall increase in coastal East Antarctica linked with southwest Western Australian drought’ in Nature Geosciences.Turns out that this region of Australia has been facing a 40-year drought which was attributed to several factors, such as ‘natural variability, changes in land use, ocean temperatures and atmospheric circulation’. After evaluating the precipitation records of the two regions (East Antarctica and southwest Western Australia), the authors report an inverse correlation, surmising that the rain which should have fallen in Australia may have moved to Antarctica, resulting in heavy snowfall.What needs to be evaluated is whether this is purely due to anthropogenic climate change and whether the study can be substantiated by constructing similar correlations in other southern hemisphere nations which also has/had similar conditions of drought.van Ommen, T., & Morgan, V. (2010). Snowfall increase in coastal East Antarctica linked with southwest Western Australian drought Nature Geoscience, 3 (4), 267-272 DOI: 10.1038/ngeo761... Read more »
van Ommen, T., & Morgan, V. (2010) Snowfall increase in coastal East Antarctica linked with southwest Western Australian drought. Nature Geoscience, 3(4), 267-272. DOI: 10.1038/ngeo761
Do you write about peer-reviewed research in your blog? Use ResearchBlogging.org to make it easy for your readers — and others from around the world — to find your serious posts about academic research.
If you don't have a blog, you can still use our site to learn about fascinating developments in cutting-edge research from around the world.
Research Blogging is powered by SMG Technology.
To learn more, visit seedmediagroup.com.