ENVIRONMENTAL ISSUES IN SOUTHEAST ASIA
Environmental problems in Southeast Asia include logging depleted rain forests and overfishing the once-plentiful fish supply in the Gulf of Thailand. The megacities of Southeast Asia can not adequately dispose of all the garbage and waste they produce.
The environmental policy across Asia has been “grow now and clean up later.” According to a 1997 Asian Development Bank report, "Asia is the world's most polluted and environmental degraded region.” During the past 30 years, Asia has lost half of its forest cover, and with it countless unique animal and plant species. A third of its agricultural land has been degraded. Fish stocks have fallen by 5 percent. No other region has so many heavily polluted cities, and rivers and lakes are among the worlds most polluted."
Asia is home to 13 of the world's 15 most polluted cities. Pollution is not just a local phenomena. It can be a global one. Scientists estimated in 2010 that one third of the ozone in Los Angeles originates in Asia.
The 1997 economic crisis resulted in a reduction of pollution as people drove less and bought fewer cars, factories reduced their output or were closed, construction ceased and development projects were scrapped. But not all news was good. Spending on the environment fell and poverty caused by the crisis led to increases in legal logging, wildlife poaching, overfishing, cyaniide fishing and slash and burn agriculture.
See the Mekong River.
Global Warming in Asia
According to a report of the Working Group II of the U.N.”s Intergovernmental Panel on Climate Change (IPCC) grain harvests in the Asian region could drop by as much as 30 percent, leading to skyrocketing food prices and the starvation of 132 million people in Asia in the 2050s, if fossil fuels continue to be consumed at the current rate. Countries with ric-growing flood plains off major river and near coastal areas could loose vast tracts of agricultural land to rising sea levels. [Source: Yomiuri Shimbun, March 29, 2007]
The report found that many Asian areas, including Japan and eastern Russia, have already seen a decline in grain harvests, a phenomenon that will make it more difficult for developing countries to meet their growing demand for food.In addition to rising temperatures caused by global warming, chronic flooding, heat waves and droughts are behind the falling harvests, the report says.
In the future, grain harvests will drop by between 2.5 percent and 10 percent in the 2020s, and 5 percent to 30 percent in the 2050s, compared with the amount harvested in 1990, the report says. Even if the mercury rises by just 0.5 C in winter, the wheat harvest in India would be badly affected, the report says.
In the event the temperature rises 2 C, rice harvests in China could plunge by between 5 percent and 12 percent, according to the report. Higher seawater temperatures in the area spreading from East Asia to Southeast Asia would drastically change fish habitats, with minnows in tropical seas most at risk, which would see fish catches decline.The melting of glaciers in the Himalayas, which serve as a natural dam, would lead to a scenario that could threaten the life of more than 700 million people who rely on meltwater, the report warns. The report predicts that if the Himalayan glaciers continue melting at the current speed, they will have almost vanished by 2035.
Global Warming in Southeast Asia
Melting Himalayan glaciers is one of the costs of global warming. Southeast Asia will suffer the impact of long-term water shortages resulting from this in part because it doesn’t have so many dams and reservoirs to store water. Water provided from rivers during the spring melt is particularly vital because it often needed for irrigation during the dry season.
According to an Asian Development Bank study: Over the coming decades, climate change will lead to decreasing rainfall in many parts of Southeast Asia, and millions will suffer from water shortages. Rice production from the region, the world's rice bowl, will appreciably decline, threatening food security. Vast tracts of high-quality forests will give way to tropical savannah and scrub land. Floods, cyclones, droughts and other extreme weather events will become more common. [Source: Ursula Schaefer-Preuss and Emil Salim, Jakarta Post, April 29, 2009, Dr. Ursula Schaefer-Preuss is Vice-President of Knowledge Management and Sustainable Development at the Asian Development Bank. Dr. Emil Salim is an economist and a former Indonesian Minister of State for Population and the Environment]
Ursula Schaefer-Preuss and Emil Salim wrote in the Jakarta Post: By the end of the century, temperatures in Southeast Asia will dramatically rise. Sea levels could rise 70 centimeters or more, inundating entire islands and low-lying coastal areas. Health threats will also rise, with deaths from cardiovascular and respiratory disease, malaria, and dengue increasing - all because of climate change. As is the case with most disasters, it is the poorest who will suffer the most.
Southeast Asia only produced 12 percent of the world's greenhouse gasses at the turn of the century, but the region's rapidly expanding population and economy means its global share of carbon emissions will increase in the future if no action is taken. The report notes that the forestry sector is the largest contributor to Southeast Asia's GHG emissions, and land use change therefore holds the key to successful emissions reduction in the region.
AFP reported: “Climate change is "a wild card for Asian development", warned an Asian Development Bank study, which stressed that Asia is already hit by more storms, floods and other natural disasters than any other region. Global warming threatens to melt the glaciers that run from the Himalayas and other mountain ranges to feed Asia's major rivers, which provide water, food, fish and power for 2.8 billion people, it said. "Climate change will affect everyone. With over half the world's population, Asia has more at stake than any other region," said the study. [Source: Frank Zeller, AFP, August 1, 2011]
Climate Change Could Spawn Mass Migrations
In March 2012, AP reported: The Asian Development Bank is warning countries to prepare for influxes of people fleeing natural disasters as climate change exacerbates rising sea levels, soil degradation and seasonal flooding. It said that one-third of Southeast Asia's population lives in at-risk areas, including Indonesia, Myanmar, the Philippines, Thailand and Vietnam. Six of the 10 countries most vulnerable to climate change are in the Asia-Pacific. Bangladesh tops the list followed by India, Nepal, the Philippines, Afghanistan and Myanmar. [Source: AP, March 13, 2012]
"Given that climate change acts as an aggravating factor for environmental degradation, it is expected to boost the number of people migrating because of environmental changes, both sudden and slow onset. Though the amplitude of these movements remains difficult to forecast, climate change is likely to become a major driver of migration in the 21st century," the report said.
It cited the Intergovernmental Panel on Climate Change, a U.N. network of 2,000 scientists, as saying that the Asia-Pacific will bear the brunt of significant temperature increases, changing rainfall patterns, greater monsoon variability, sea-level rise, floods, and more intense tropical cyclones. Most scientists expect such changes to accompany a rise in the planet's temperature caused in part by greenhouse gasses from burning fossil fuels for electricity and transport.
The region is particularly vulnerable because of its high population density and long coastlines. Recent examples of such migration include Papua New Guinea, where residents of Carteret and neighboring atolls moved to the island of Bougainville because of rising sea levels. In 2010, more than 10 million Pakistanis were displaced by monsoon rains and flooding along the Indus River basin, and last year, a typhoon ravaged the southern Philippines, displacing more than 300,000 people.
Green Stimulus for Southeast Asia
Ursula Schaefer-Preuss and Emil Salim wrote in the Jakarta Post: “Hundreds of islands in Indonesia and the Philippines, large swaths of VietNam's Mekong Delta, and great portions of Thailand and Singapore's sovereign territory are all under imminent threat. Why, then, the deafening silence? Why no call for urgent action? Perhaps it is because the foe is not a sovereign state, but climate change. [Source: Ursula Schaefer-Preuss and Emil Salim, Jakarta Post, April 29, 2009, Dr. Ursula Schaefer-Preuss is Vice-President of Knowledge Management and Sustainable Development at the Asian Development Bank. Dr. Emil Salim is an economist and a former Indonesian Minister of State for Population and the Environment]
A 2009 report by the Asian Development Bank - The Economics of Climate Change in Southeast Asia: A Regional Review - explains that countries do not face an either-or choice between addressing the financial crisis and climate change. Failure to address either threat will have catastrophic consequences. If the world continues with "business as usual", Southeast Asian nations could experience combined damages equivalent to more than 6 percent of their countries' gross domestic product on an annual basis, dwarfing the costs of the current financial crisis.
Southeast Asian nations should address the dual threats of the financial crisis and climate change by introducing effective green stimulus programs - as part of larger financial stimulus packages - that can simultaneously shore up their economies, create jobs, reduce poverty, lower carbon emissions, and make them more prepared for the worst effects of climate change. This means improving water management, preparing the agriculture sector for climate change impacts, safeguarding forests and coastal resources, and preventing infectious disease outbreaks.
As good global citizens, Southeast Asian nations will also have an increasing responsibility to curb the emission of greenhouse gasses (GHG) that cause global warming. The report notes that the forestry sector is the largest contributor to Southeast Asia's GHG emissions, and land use change therefore holds the key to successful emissions reduction in the region. This can be achieved by reducing deforestation and land degradation, encouraging the planting of new forests and reforestation, and improving forest management.
The energy sector also offers vast, untapped opportunities for emissions reduction. Energy efficiency improvement will allow Southeast Asian nations to mitigate their CO2 emissions as much as 40 percent by 2020. This 'win-win' measure can actually be implemented at a negative net cost, with energy cost savings outweighing the expense of mitigation.
Other important emissions-reducing measures include cleaner transport solutions, sustainable farm management, and the increased use of renewable energy sources like wind, biomass and solar. Implementing these measures would require the development of comprehensive policy frameworks, incentives for private-sector action, elimination of market distortions -and ample financial resources.
International funding and technology transfers will be essential for success, as will regional cooperation, particularly in dealing with cross-boundary issues associated with global warming, such as water resources management, natural disasters, and disease outbreaks. Many of these measures can be implemented immediately, as components of broader fiscal stimulus packages, creating much-needed jobs for the region's people.
Air Pollution in Asia
Air pollution in Asia is caused primarily by the burning of wood and fossil fuels. The World Health Organization (WHO) estimates that air pollution in Asia is responsible for 537,000 premature deaths a year. William Pesek of Bloomberg wrote: Bad air is becoming an Asia-wide problem. The region's booming economies are paying all too little attention to the negative side effects of rapid growth. The question, really, is this: will Asia choke on its own economic success? "Asia is at a point where it definitely needs to find a balance between fast growth and getting control over the environment," says Wu Hai, a Beijing-based partner at consulting firm McKinsey & Co. [Source: William Pesek, Bloomberg, December 2006]
This all sounds very unfair. Europeans polluted plenty when they industrialized in the 19th century. Americans did more than their share in the 20th century, and still do with their sport utility vehicles and failure to get serious about the risks of global warming. Shouldn't Chinese, Indians and other developing Asians have the right to pollute as much as the West did? In a perfect world, yes. It's unclear, though, that this world of ours is capable of coping with almost 3 billion Asians growing richer and polluting the way Westerners have.
In a recent report on China's economy, the Economist Intelligence Unit put it quite well: "Think of the worst excesses of global industrialization in the past 100 years, factor in a population of 1.3 billion, and then you will get some idea of the scale of environmental challenges created by China's rapid growth."
The future hardly looks brighter when you consider that most power is still coal-generated, vehicle ownership is rising fast and environmental laws are as hazy as the sky. Consider how Asia's skies will look when 400 million Chinese, 400 million Indians and hundreds of millions of Southeast Asians own one or more cars. That's on top of factories throughout the region maximizing profits by burning more and more coal. All this will lead to increasing health risks, slower growth, less foreign investment, increased government debt and higher bond yields.
The bottom line is that many parts of Asia are reaching their environmental limits and the blind pursuit of gross domestic product just isn't possible anymore. In the year ahead, environmental issues simply will have to become a bigger blip on the radar screens of Asian governments and investors alike.
Asia’s Brown Cloud
An “Asian brown cloud,” estimated to be 3.2 kilometers thick, hangs over much of southern Asia. It is believed to be to be connected with hundreds of thousands of respiratory disease deaths. Layers of brown gunk created in India mainly from cooking and heating fires made from low-quality coal, wood, and cow dung extend southward for more than 1,600 kilometers. When he first noticed the cloud on a flight from Bombay to the Maldives, V. "Ram" Ramanathan, an atmospheric scientist from the Scripps Institution of Oceanography, told U.S. News and World Report, "The haze just kept going and going. It didn't even seem to thin out. I was thinking, this is something big." [Source: Charles W. Petit, U.S. News and World Report, March 17, 2003]
U.S. News and World Report reported: “The vast brown cloud often extends thousands of miles east, across China. A stew of dust, ash, and smoke from fires and industry, the cloud threatens the health of the billions who live under it. The fine particles, or aerosols, also warm some areas and cool others, drying up storm clouds and perhaps even shifting India's life-giving monsoon. In many places the haze swamps greenhouse gases as a climate-changing force, say scientists. The atmospheric havoc in Asia may even play a role in El Niño.
“Ramanathan and his Scripps colleague Paul Crutzen, a chemist and Nobel laureate, made a start with their Indian Ocean Experiment in the late 1990s, which studied haze from a score of ground stations and from aircraft. Their glimpses of the cloud's extent and impacts helped set off an explosion of similar studies across India, off Japan and Korea, and in China, which spawned a United Nations effort called Project Asian Brown Cloud.
“Coal is a major source of Asiam air pollution. Across Asia, coal heats houses and cooks meals. Smoke from agricultural burning and wildfires adds to the brew. In China, the haze sometimes starts as dust blowing off western deserts, "but it picks up all kinds of toxic pollutants as it travels," says F. Sherwood Rowland, a University of California-Irvine chemist who received a Nobel Prize for work on ozone. "We can detect Asian aerosols blowing all the way across the U.S."
“Cameras on early weather satellites were calibrated for clouds but not hazes. But new full-color satellite camera systems now send images of a nearly continuous, 2-mile-thick blanket of sulfates, soot, organic compounds, dust, fly ash, and other crud draped across much of India, Bangladesh, and Southeast Asia, including the industrial heart of China. Lorraine Remer, who analyzes satellite data at NASA's Goddard Space Flight Center said he was shocked by satellite data that showed how much the brown cloud dims light. Across much of Asia, they were several times higher than anything ever seen in American smog. "We were standing there not believing it," she says. In and around India, the researchers found sunlight was reduced by 10 percent. Crop scientists say this is enough to reduce rice yields by 3 percent to 10 percent across much of the country.
Asia’s Brown Cloud Blamed for Flooding and Drought
Charles W. Petit, wrote in the U.S. News and World Report, “Researchers are coming to realize that, through a long chain of effects, the brown cloud may also be to blame for drought and flooding. Scientists' understanding of how aerosols shape climate is not nearly as well developed as it is for greenhouse gases like carbon dioxide, still No. 1 on any list of human impacts on climate. "But one common aspect," says Ramanathan, "is that the haze and its heating of the atmosphere is sufficient to disturb climate a lot."[Source: Charles W. Petit, U.S. News and World Report, March 17, 2003]
“Unlike the whitish sulfate particles from cleaner-burning power plants in the United States and Europe, the Asian hazes are dark with soot. As a result, they absorb sunlight and can double the rate at which it warms the atmosphere several thousand feet up, while shading and cooling the ground below. Some scientists think that the net effect is to boost global warming. But the more certain impact of the hazes is on rainfall, says Jeff Kiehl of the National Center for Atmospheric Research in Boulder, Colo. "They are radically changing the temperature profile of the atmosphere in many areas, with a big impact on where rain falls and how much."
“By cooling the northern Indian Ocean, the haze reduces evaporation, cutting the water supply for rainfall. On land, the warm air aloft acts as a lid on cloud formation, quashing the convection that feeds thunderstorms. And the aerosols themselves seed the formation of tiny mist particles--so many that they suck water out of the air and choke off the growth of larger drops that would fall as rain. While the haze particles dry out the land, the rain does fall over the sea, where larger, natural sea-salt particles promote droplet growth. "We're shifting rain from the land to the ocean," says Daniel Rosenfeld of the Hebrew University of Jerusalem. “At least that's the theory, and there are signs it may be happening. Some computer climate models predict that the hazes over India should displace the annual monsoon rains, leading to floods in the south and east of the country while drying the north and shrinking the vital Himalayan snowpack. "That's just the pattern we are starting to see emerge," says Surabi Menon of the Goddard Institute for Space Studies in New York City.
“In southeastern China, where haze has cut sunlight by 2 percent to 3 percent every 10 years since the 1950s, temperatures are dropping, while rising elsewhere in the country, presumably because of greenhouse gases. The changed temperature patterns have rerouted storm tracks, one recent Chinese study said. The study blamed the shift for severe floods in the nation's south in recent years, coupled with drought in the north. It ranked the new weather pattern as the greatest sustained change in China's climate in more than 1,000 years.
“Some scientists also suspect that the pollution cloud could be cooling the sea surface and slowing evaporation in the far western Pacific, off Asia. The effects could ripple across half the globe to the United States, because the western Pacific is the breeding ground for El Niños, the bouts of Pacific warming that change rainfall across the Americas and beyond.
Indian Ocean Pollution Haze Linked to Melting of Himalayan Glaciers
In 2007, AP reported: “Huge haze clouds over the Indian Ocean contribute as much to atmospheric warming in Asia as greenhouse gases and play a significant role in the melting of the Himalayan glaciers, according to a study published Thursday. Unmanned measuring devices were sent into the haze pollution, known as Atmospheric Brown Clouds, over the Indian Ocean in March 2006 near the island of Hanimadhoo to measure aerosol concentrations, soot levels and solar radiation. [Source: Michael Casey, Associated Press, August 3, 2007]
“Researchers concluded that the pollution — mostly caused by the burning of wood and plant matter for cooking in India and other South Asian countries — enhanced heating of the atmosphere by around 50 percent and contributed to about half of the temperature increases blamed in recent decades for the glacial retreat. Veerabhadran Ramanathan said his team's research shows the brown clouds are an additional factor in the melting of glaciers, along with overall global warming caused by greenhouse gas emissions.
“Until this study, published in the journal Nature, scientists believed the brown clouds mostly deflected sunlight, cooled the atmosphere and did not contribute much to the effects of global warming. But Ramanathan said their observations show particles also absorbed sunlight and warmed the atmosphere much more than previously believed. "All we are saying is that there is one other thing contributing to atmospheric warming and that is the brown cloud," said Ramanathan, a chief scientist at the University of California San Diego's Scripps Institution of Oceanography in La Jolla, Calif.
“Syed Iqbal Hasnain, a senior fellow at the Center For Policy Research in New Delhi and a glacial expert, agreed brown clouds could be a factor in the melting of the glaciers that supply water to most Asian rivers. But he said more research was needed to understand why the Himalayan glaciers in China are also melting at a dramatic rate. "Glaciers across Himalaya are receding, but their response is dependent on many factors like size, orientation and intensity of monsoonal moisture," Hasnain, who was not connected with the study, said in an e-mail message from New York. "There is a great urgency on the part of the international scientific community to establish high altitude research stations across Himalaya and monitor climate accurately to develop scientifically correct models."
“Scientist have expressed concerns the Himalayan glaciers will melt entirely and the rivers will run dry for months at a time, fed only by annual rains like the monsoon that sweeps across the subcontinent every summer. Melting is exacerbated by India's and China's fast-growing, coal-fed economies. Scientists say the glaciers are melting at a rate of up to 49 feet a year and predict they could shrink even more with temperatures projected to rise as much as 11 degrees by 2100.
Ramanathan established a pilot project with the Energy Research Institute in New Delhi that would provide fuel alternatives to 1,000 families in Kumaon region in the foothills of the Himalayas. If the project proves successful, he said he is hoping it can be expanded in other parts of India. "If the pollution increases, the glacier retreat will be much worse than projected," he said. "It now depends on what energy path that Indian, China and Asia will take."
Soot From Southern Asia Linked to Arctic Melting
Miguel Bustillo wrote in the Los Angeles Times: “Soot pollution from southern Asia appears to be contributing to climate changes at the North Pole, raising atmospheric temperatures and speeding up the melting of snow and sea ice, according to a study by scientists at NASA. The researchers, who have been using satellite imaging to track the effects of soot, or black carbon emissions, believe they have found a link between the timing of Arctic warming and ice loss and deposits of tiny particles from man-made pollution during the late 20th century. [Source: Miguel Bustillo, Los Angeles Times, March 24, 2005]
“The findings, which support earlier conclusions, demonstrate that the climate changes affecting the Arctic region are complex and may be a result of traditional pollution as well as global warming from the release of heat-trapping greenhouse gases. The findings also show that most of the pollution in the Arctic does not come from smokestacks and tailpipes in the developed world, but from industrial emissions in South Asia and forest fires and the burning of other vegetation around the planet.
“The study, co-authored by Dorothy Koch of Columbia University and James Hansen of NASA's Goddard Institute for Space Studies, was published recently in the Journal of Geophysical Research. "Soot is a particular concern in the Arctic because it can accelerate the melting of the ice and snow," Koch said in an interview. "The standard knowledge has always been that most of it comes from Northern Europe and Asia. We were surprised to find that much of it comes from further south."
“When soot particles fall on ice, they darken the surface. The seemingly minuscule shift in coloration can make the ice more prone to absorb sunlight instead of reflecting it, and can thus cause it to melt more easily. Similarly, tiny soot particles can warm the air and have been shown to alter weather patterns and affect the formation of clouds, which collect condensation around tiny airborne particles known as aerosols.
“Pollution particles can increase the number of aerosols in clouds, which in some cases have been found to reduce the amount of rain that the clouds release. In other cases, research suggests that the tiny flecks can cause clouds to stay together longer, resulting in more intense precipitation when the clouds finally release their moisture.
“During the 1980s, much of the soot pollution above the Arctic was believed to come from Russia and Europe. Though those emissions have declined, pollution from southern Asia appears to have increased. About a third of the soot over the Arctic now comes from South Asia, which has the highest industrial soot emissions in the world, says the study, which used computer models and satellite data to track the pollution. Another third comes from the burning of vegetation and natural materials around the world; the rest comes from Russia, Europe and North America.
Asian Air Pollution Generates Stronger Storms over Pacific
Pollution from Asia is helping generate stronger storms over the North Pacific, according to research by a team led by Renyi Zhang of Texas A&M University,. Satellite measurements have shown an increase in tiny particles generated from coal burning in China and India in recent decades, researchers report in Tuesday's issue of Proceedings of the National Academy of Sciences. Changes in the North Pacific storm track could have an impact on weather across the Northern Hemisphere. [Source: Randolph E. Schmid, AP, March 6, 2007]
Zhang’s team studied pollution and clouds between 1984 and 2005, concluding that increasing particles enhanced the cloud updraft to generate more intense thunderstorms than previously. Comparing 1984-1994 with 1994-2005 they found an increase of 20 percent to 50 percent in deep convective clouds. "The intensified storms over the Pacific in winter are climatically significant," the researchers wrote. "The intensified Pacific storm track can also impact the global general circulation."
The Pacific storm track, they noted, plays a critical role in global atmospheric circulation, and altering this weather pattern could have a significant impact on the climate. A particular threat, they added, is the potential for increased warming of polar regions. The research was supported by National Science Foundation, Department of Energy and the National Aeronautics and Space Administration.
Arsenic Risk High in Parts of Southeast Asia
In July 2008, AFP reported: “Eastern Sumatra, the Irrawaddy delta in Myanmar and Cambodia's Tonle Sap lake are among areas in Southeast Asia facing a high risk of arsenic contamination in the water, according to a study published online in the journal Nature Neuroscience. The researchers use innovative digitalised techniques, drawing on geology, geography and soil chemistry, to compile a "probability map" of naturally-occurring arsenic concentrations in five Southeast Asian countries and Bangladesh. [Source: AFP, July 11, 2008]
“The map is intended as a useful pointer for health watchdogs, urban planners and water engineers worried about concentrations of this poison in groundwater supplies but lacking the funds to carry out wide-scale analysis of water samples. The Swiss-led study combined several methods to compile its probability model. These included knowledge about sediments whose textures and chemical or bacterial properties could release arsenic from the local ore, thus contaminating aquifers. Also factored in were areas with flat, low-lying topography. Arsenic contamination is rarely found in places with slopes.
“The benchmark for risk was the World Health Organisation (WHO) guideline of 0.01 milligrams of arsenic per litre in drinking water. The study predicted that in Bangladesh -- which has the worst arsenic contamination in the world -- the risk of water breaching this guideline was highest in the south-centre of the country and in the northeastern Sylhet basin. This prediction concurred with water samples previously taken and analysed from tube wells in Bangladesh.
“High probabilities of arsenic contamination were also seen for the deltas of the Irrawaddy in Myanmar and the Red River in Vietnam, for the Chao Praya basin in central Thailand and for the organic-rich sediments of the flood plain of Cambodia's Tonle Sap lake. The computer model said an area of about 100,000 square kilometres (38,600 square miles) on the east coast of Indonesia's main island, Sumatra, was likewise "prone to high risk" of contamination above the WHO benchmark.
“This prediction was then borne out by samples taken from a zone in Sumatra deemed to have high-risk and low-risk aquifers. However, many wells in this area are deep and draw water from below the water-bearing sediments which have the arsenic problem, the study says. "The prediction map is a useful tool for identification of areas at risk of arsenic contamination, but... understanding the local geology as a function of depth is of vital importance for specific areas," it cautions.
“In Bangladesh, tens of millions of people are potentially exposed to arsenic-tainted water, boosting the danger of skin lesions, respiratory illness and cancer. The risk comes from so-called shallow tube wells which were drilled in the 1970s and 1980s, ironically in a bid to provide rural Bangladeshis with safe water. Millions of these pipes were installed. The new study is lead-authored by Michael Berg of the Swiss Federal Institute of Aquatic Science and Technology in Duebendorf.
Why Rice Absorbs So Much Arsenic
In 2008. Reuters reported: Scientists in Japan may have discovered why rice absorbs so much arsenic from the soil, paving the way for fresh efforts to block the potentially harmful element from Asia's staple food. In the Proceedings of the National Academy of Sciences, they said they had identified two proteins in rice plants that appeared to transport arsenic from the soil to the grain. [Source: Tan Ee Lyn, Reuters, July 14, 2008]
Using mutant paddy that did not have these two proteins, the experts found sharply reduced levels of arsenic. "We used mutant paddy (in which) these two transporters were knocked out and we saw decreased arsenite in both the stalk and rice grain," said Ma Jianfeng at Okayama University's Research Institute for Bioresources.
Arsenic occurs naturally in the environment and was used in small amounts in the past to cure diseases like syphilis. But prolonged exposure to arsenic, like in drinking water, has been linked to cancers of the lung, bladder and skin, numbness, cardiovascular disease and diabetes. Arsenic poisoning is especially serious in places such as Bangladesh and West Bengal in India, where arsenic-contaminated groundwater is used for irrigating rice crops, resulting in arsenic accumulation in soils and grain.
However, Ma's team found the absence of the two transporter proteins reduced the absorption of silicon from the soil. Silicon occurs naturally and is important for the growth and productivity of rice plants. It also protects rice from pests and disease. "Silicon concentration was also decreased. So in future we have to try to change the selectivity, to allow silicon to be transported but not arsenic. That's what we have to do in future," Ma told Reuters in a telephone interview.
Ma also recommended that more silicon fertilizers be used. "Silicon and arsenic use the same transporters ... (using) more silicon fertilizers in paddy fields (will result in) more silicon uptake and less arsenic," Ma said. A Scandinavian team of researchers recently found that a gene that helps plants fight off fungal infections appears to allow plant cells to absorb arsenite. That team hopes that their findings could one day lead to genetically engineered crops that allow rice, for example, to accumulate silicon but not arsenic.
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Last updated November 2013