Ecoratorio’s article on Human-Animal Conflicts in ‘The Ship’ , a 100th anniversary publication of St. Anne’s College, University Of Oxford, UK.

We came to know that Sarah Stephen’s article exploring  Human-Animal Conflicts was published in the 100th anniversary edition of ‘The Ship^{', a} publication of St. Anne’s College, University of Oxford, UK, where she had been a student. You can read it here

http://www.st-annes.ox.ac.uk/fileadmin/sta/documents/Alumnae___Friends/Publication_PDFs/The_Ship_2011-LB.pdf

Why where you work could influence risk of breast cancer

Workplace plays a pivotal role in influencing cancer risk

WHO statistics show that 19% of all cancers are attributable to the environment including work settings, and result in 1.3 million deaths annually worldwide. In reality, the actual figure could be much higher than this, as an individual’s genetics, physiology, exposure to environmental cancer causing agents (carcinogens) and life style invariably crisscross and therefore it is seldom possible to study environmental exposure and cancer in isolation. One thing is clear, that cumulative exposure to certain environmental agents, could either initiate cancer, or be involved in its progression. Breast cancer is the most common cancer among women in many industrialised nations. Roughly 48,000 women in the UK and 226, 870 women in the US get breast cancer each year.  Hormones, notably estrogen, play an important role in breast cancer progression.  Several studies have shown that environmental agents exist, that interfere with hormones by mimicking them or by disrupting them called endocrine disruptors.  Those that mimic the effects of estrogens are called xenoestrogens. Well known synthetic  xenoestrogens  include Polychlorinated biphenyls (PCBs), BPA (Bisphenol A)and phthalates, which are widely used industrial compounds.

Whilst several laboratory studies implicate a link between environmental exposure and breast cancer, large scale population studies have been inconclusive. This is understandable as the laboratory systems are simplistic and can study factors in question in isolation. In the 1990s, NIEHS and the NCI conducted a large study on the environmental causes of breast cancer, to investigate the increased breast cancer rate in Long Island, New York . In the study, scientists focused their investigation on three widespread pollutants - organochlorine pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons (PAHs), to which many of the Long Island residents had been exposed. Whilst a small increase in breast cancer risk was due to PAH exposure the researchers were unable to identify any environmental factor that could be responsible for the high incidence of breast cancer area.

Approximately the same time as the Long Island studies, across the border, in Essex and Kent counties of Southern Ontario, Canada, the local cancer hospital staff raised alarm about industrial workers developing breast cancer. This area then became the subject for studies which showed a link between cancer and industrial/agricultural work settings, but the questions explored in the study were not complete. A subsequent study in this region ( recently published) which has a stable population and diverse modern agriculture and industry was used for more thorough investigations and provided interesting observations. Cases were recruited over a six year period from mid 2002 through to  mid 2008 and  the occupations of 1006 women who had breast cancer and 1146 randomly selected women from the community without this disease were analysed . The results showed that women working in environments with risk of high exposure to carcinogens and endocrine disruptors had a high risk of developing breast cancer. Notable sectors with high risk were the agricultural sectors (where pesticides are used), automotive plastics manufacturing sector, food canning industry, metalworking industry and bars/gambling industry (second hand smoke exposure risk). The researchers also found that premenopausal breast risk was highest in those women working in the plastics industry and food canning industry.

The study provides resounding evidence for linking occupational exposure of endocrine disruptors/ carcinogens and breast cancer risk warranting further studies. With people generally spending an average of 8 hours at work, working environments are major influences of cancer risk. Employees  are often not made aware of  their risks of harmful exposures at work and  how they could reduce exposures. Evidently, most of the exposure risks for occupational cancers are preventable.  A clean working environment should be the basic right of a worker. A resolution by the World Health Assembly in 2005 on cancer prevention and control urged countries to develop programmes aimed at reducing cancer incidence and mortality. This resolution advocated for special attention to cancers prevention by avoiding exposure to chemicals at the workplace and in the environment.  Though, it remains to be seen what cancer prevention programmes have been developed or implemented in the workplace, to what extent,  and how it compares between different countries.

References:
Brophy, J., Keith, M., Watterson, A., Park, R., Gilbertson, M., Maticka-Tyndale, E., Beck, M., Abu-Zahra, H., Schneider, K., Reinhartz, A., DeMatteo, R., & Luginaah, I. (2012). Breast cancer risk in relation to occupations with exposure to carcinogens and endocrine disruptors: a Canadian case--control study Environmental Health, 11 (1) DOI: 10.1186/1476-069X-11-87

DeMatteo, R., Keith, M., Brophy, J., Wordsworth, A., Watterson, A., Beck, M., Ford, A., Gilbertson, M., Pharityal, J., Rootham, M., & Scott, D. (2012). Chemical Exposures of Women Workers in the Plastics Industry with Particular Reference to Breast Cancer and Reproductive Hazards NEW SOLUTIONS: A Journal of Environmental and Occupational Health Policy, 1 (-1), 427-448 DOI: 10.2190/NS.22.4.d

http://www.ncbi.nlm.nih.gov/pubmed/23164221

http://www.ncbi.nlm.nih.gov/pubmed/23207955

A common fungicide used on leafy vegetables could make people fat

Obesity is on the rise globally. World Health Organization forecasts 2.3 billion overweight adults in the world by 2015 and greater than 700 million of them to be obese. In the UK, as in most industrialised nations, obesity is increasing. Figures show that 62.8% of UK adults (aged 16 or over) were overweight or obese as are 30.3% of children (aged 2-15). A recent report released by the NHS (National Child Measurement Programme) indicates that in the UK 1 in 3 of primary school children in the last year are overweight/obese.

The health implications of obesity are enormous. Studies suggest that obesity could have a causal effect or increases the risk of  several diseases, notably type 2 diabetes, heart disease,  liver disease, and selected cancers. Three major factors that influence obesity are diet, environmental factors and physical activity.

Several studies have shown that maternal diet and exposure to environmental agents has a crucial effect not only on the health of the woman, but also on foetal and child health. Our earlier post looked at how exposure of pregnant mothers to pesticides can leadto obesity in children and put them at risk for heart disease. We also discussed one study where maternal exposure of phthalates make their way to the offspring and can have detrimental effects.

Chemicals that increase either the number of fat cells in an organism or the amount of fat stored in those cells and promote weight gain are called obesogens. Notable culprits are environmental agents such as bisphenol A, phthalates, organophosphate pesticides etc. Some scientists hypothesise that the obesity epidemic that is seen could have links to the increased exposure  to pesticides.

Triflumizole (TFZ) is an imidazole fungicide that is used during the cultivation of  many green leafy vegetables.Whilst TFZ is not classified as toxic, its effect on development is unknown. A recent study by researchers in California shows that this fungicide promotes adipogenesis (the process by which precursors of fat cells become fat cells) in laboratory experiments with human and mouse cells in culture and also in animal models. They found that stem cells that have the potential to develop into bone, cartilage, or fat cells,  upon treatment with the fungicide, ended up as fat cells. The researchers also observed that levels of genes related to obesity increased with treatment of both human and mouse cells. Exposure with the fungicide also resulted in fat accumulation. More interestingly, exposure of pregnant mice with the fungicide at very low doses (roughly 400 fold below the levels that show no observed adverse effect ) increased mass of fat depot (where fat tissue is stored) but were not shown to increase body weights. The study further showed that blocking PPAR gamma (Peroxisome Proliferator Activated Receptor gamma)  pathway using a specific antagonistic drug, stopped the differentiation into fat cells  suggesting that that  TFZ acts through this receptor. PPAR is found in the nucleus of the cell ( hence called nuclear receptor)and functions as a transcription factor (that which switches on  genes and controls the levels). Interestingly other nuclear receptors include the receptors for estrogen, thyroid hormone, retinoic acid, Vitamin D etc. These receptors have also been shown to interact with each other. It appears that TFZ could also be grouped under ‘endocrine disruptor’  (hormone disruptor). 

Very little information exists about the exposure and the levels of TFZ in humans. The scientists suggest that further studies that monitor the levels of TFZ and its metabolites in humans must be carried out to decipher the role of the chemical’s potential influence on obesity. However one fact is clear that TFZ is now in the list of potential new obesogens. Eating green leafy vegetables is good for health, but this maxim only holds true when it is  pesticide/fungicide free.

PS- TFZ is also licensed for used on a variety of fruits and vegetables in the US (Personal communication with Dr. Blumberg, one of the authors of this study). 

Reference:
Li, X., Pham, H., Janesick, A., & Blumberg, B. (2012). Triflumizole is an Obesogen in Mice that Acts through Peroxisome Proliferator Activated Receptor Gamma (PPARγ) Environmental Health Perspectives DOI: 10.1289/ehp.1205383 

When two worlds collide : Tales from two continents

Western Ghats-  A hotspot of biodiversity

With advances in health care, eradication and effective control of fatal diseases, the world population is on the rise. One collateral effect is the enormous consequence of such an increase on natural resources including land. Humans with their might are encroaching into the forests- the natural habitat of wild animals. Consequently, whilst human inhabited lands increase, the forests decrease proportionally. As has been highlighted repeatedly, the areas in the world that are maximally impacted are the tropics, which are the areas of highest human population density. Here, forest areas are cleared, making way for habitable land (legal and illegal), agricultural land (be it subsistence farming, large scale crop cultivation, or as land for livestock grazing),  stone quarrying, or the wood from the forest is used for fuel and furniture. The consequences of all these actions are colossal, and have led to brutally endangering the existence of flora and fauna. One group of animals that are gravely affected are the larger mammals, whose territory encompasses larger areas. The Royal Bengal Tiger, a subspecies of Tiger, is in the IUCN’s list of endangered species with only about 2500 animals alive today. A census report released in, 2011 by the National Tiger Conservation Authority, estimates the current tiger number in India at 1,706.

Kerala, one of the most densely populated states in India and at 859 persons per sq km, is thrice as settled as the rest of India. Once blessed with luxuriant forests; nearly three quarters of the geographical area of Kerala was under dense forest cover at the middle of nineteenth century, human activities have restricted the forest cover to 20 to 24 % area, based on the source for the facts. The Western Ghats comprise a range of mountains along the western side of India extending to Kerala and is abundantly diverse and is the habitat of at least 325 endangered flora and fauna species. When the Western Ghats was designated as a UNESCO World Heritage Site, as one of the eight hotspots of biological diversity in the world, the Kerala minister of forests highlighted the enormous challenge of protecting this fragile yet diverse landscape citing the pressures of development and population growth.

The forests in Kerala in the Western Ghats are of different types, depending on the area, elevation, proximity and other environmental factors, consisting of tropical rain forests, tropical moist deciduous forests, tropical dry deciduous forests, montane sub tropical forests, sholas, reed brakes, grass lands,  pockets of temperate forests and barren hillocks. The diverse forests promote diversity of animals and are home to endemic species. Estimates suggest that 17% of the world’s tigers live in the Western Ghats. There are 17 wildlife sanctuaries and 5 national parks, and 1 community reserve – areas that are legally protected, in Kerala. However human- animal conflicts occur as have been previously discussed in our blog (http://ecoratorio.blogspot.co.uk/2011/07/fine-line.html)  in areas where the activities of the parties overlap, and that is not that difficult in Kerala with such high population density.  Occasionally cases are reported in the press, where a tiger, leopard, bear or elephant strays into the human communities. Whilst sometimes, the animals are coaxed into retreating from the human settlements, often their foray has disastrous consequences. The Western Ghats run throughWayanad which has a wildlife sanctuary that is shared by the neighbouring states and has a high tiger and elephant density. Earlier this year, a tiger strayed into coffee plantation in Wayanad district in Kerala. The tiger that had strayed into the plantation was reported to have preyed on domestic animals, was successfully trapped by officials and then released back into the wild ; an example of a situation which had gone according to plan. But such stories are exceptions as exemplified by the recent tragic incident. Recently, a tiger strayed into avillage area, again in Wayanad, reportedly preying on domestic animals. The wildlife authorities, attempted to tranquilize the animal. The first ‘tranquilizing’ did not affect the animal and the animal escaped. Meanwhile an ‘uncontrollable crowd’ had surrounded the forest officials on the witch hunt. After some time, the authorities and the mob found the agitated animal. The officials tried to tranquilize it again.  The animal was understandably violently aggressive, and was this time was repeatedly shot at and killed by the forest officials. It was a 10 year old male tiger. 

A Tiger at the London Zoo. Are tigers only going to be safe in captivity? (Photo : Sarah Stephen)

Environmentalists and environmental enthusiasts are bitter and distressed at the outcome. One environmentalist  who has worked extensively on biodiversity  in the Western Ghats condemned what had happened as ‘barbaric and insane’. He commented, ‘The hunting of this tiger was carried out by creating panic and insecurity among the public, that this tiger which had killed so many livestock, will eventually become a man eater.’ Several questions remain as to why the authorities resorted to the cold blooded killing of the tiger in broad daylight. It has been alleged that when the tiger embarked on the cattle hunt; the people were infuriated, blocking roads, setting ablaze the forest office, and demanding that the tiger be shot dead and that the authorities appeased the people by killing the animal. The environmentalist added, ‘The mass search of the forest areas with gunmen and a huge uncontrollable crowd following them was not the way to tranquilize an animal.’  Some sections of the media say that the story is much more complicated than what it appears to be and that illegal land mafia gangs are behind this. Allegations are rife that these unscrupulous cliques, who wanted the forests to be cleared for land, incited scare among the people in the pretext of the tiger menace, and that the animal paid a heavy price.

A task force will now conduct an independent enquiry.

Despite such incidents, some hope remains, a wildlife survey of 2011 indicates that in the state, the elephant population is growing.

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Closer to home, a few weeks ago, one peaceful Sunday afternoon was interrupted by the sound of a gunshot. As the hunting season has started in the county, it is not uncommon to see people dressed in hunting attire, en route hunts and distant sounds of shots being fired are not uncommon. But this time, the deafening noise was closer to our house. It transpired that someone had shot two squirrels. For some time, it had been a common sight seeing squirrels scurrying up and down with nuts and burying them in the gardens. They had provided unlimited entertainment to the enclave where we live. Brown squirrels are classified as vermin and can be legally shot. However, I will never comprehend the mentality of macabre recreational shooting.

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PS: If you witnessed the tiger incident or have comments on the issue, please use the comments field to voice your opinions. 

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References:

http://www.fao.org/docrep/v5200e/v5200e0b.htm

http://www.wwfindia.org/about_wwf/critical_regions/western_ghats/

http://wwf.panda.org/what_we_do/where_we_work/western_ghats/

http://whc.unesco.org/en/list/1342

http://animals.nationalgeographic.co.uk/animals/mammals/bengal-tiger/

http://www.iucn.org/?6481/IUCN-Council-statement-on-the-tiger.

http://keralaforest.gov.in/index.php?option=com_content&view=article&id=534&Itemid=327

http://www.ndtv.com/article/south/kerala-welcomes-unesco-s-decision-to-give-western-ghats-world-heritage-status-240826

http://timesofindia.indiatimes.com/city/kozhikode/NTCA-to-conduct-independent-probe-into-Wayanad-tiger-killing/articleshow/17484167.cms

http://www.thehindu.com/news/states/kerala/straying-tiger-meets-with-a-bloody-end/article4159420.ece

http://www.thehindu.com/news/states/kerala/tiger-killed-in-wayanad-was-not-a-maneater-maneka/article4160564.ece

 http://www.manoramaonline.com/cgi-bin/MMOnline.dll/portal/ep/malayalamContentView.do?contentId=12949143&programId=1073753760&tabId=11&contentType=EDITORIAL&BV_ID=@@@

http://www.thehindu.com/news/states/kerala/article3240036.ece

http://www.coplac.be/Tropical-Forests.1713.0.html?&MP=1627-169

http://www.forest.kerala.gov.in/index.php?option=com_content&view=article&id=43&Itemid=273

http://keralaforest.gov.in/index.php?option=com_content&view=article
http://www.thehindu.com/todays-paper/tp-national/forest-officials-blame-land-mafia-for-protests/article4118109.ece.