The deadly arsenic "time bomb"Published by MAC on 2007-08-30
The deadly arsenic "time bomb"
30th August 2007
It's not widely appreciated that arsenic is a toxic heavy metal employed in a variety of industrial applications (as arsenate), as well as being a noxious byproduct of metals smelting, coal-fired power plants, incineration, and mining.
Last week, Hurricane Katrina was held to blame for severe arsenic contamination recently discovered in New Orleans schoolyards. However, the state Department of Environmental Quality says this predated that climactic event. And threats elsewhere from historic arsenic poisoning in soils and groundwater are often ignored.
A few days after this disturbing news broke from New Orleans, a Cambridge University (UK) researcher revealed that some 140,000,000 people are currently being affected by arsenic poisoning around the world - half of them in South and East Asia.
The MAC website took up this vital issue three years ago.
Let's hope another three years don't pass before these issues are thoroughly addressed and, along with them, the contribution that mining makes to the scourge.
Arsenic in Water a Risk to 140 Million People
30th August 2007
LONDON - Naturally-occurring arsenic in drinking water poses a growing global health risk as large numbers of people unknowingly consume unsafe levels of the chemical element, researchers said on Wednesday.
The problem is bigger than scientists had thought and affects nearly 140 million people in more than 70 countries, according to new research presented at the annual Royal Geographical Society meeting in London.
Arsenic can cause lung disease and cancers, even long after people stop drinking contaminated water, said Peter Ravenscroft, a researcher at the University of Cambridge.
"What is new is the extent of arsenic pollution is much bigger than people realised," Ravenscroft said in a telephone interview.
"There is a very important connection between arsenic in water and arsenic in food, especially where people grow irrigated corps." World Health Organisation guidelines set a safe limit of 10 parts per billion of arsenic in water supplies but tens of millions of people in the world drink unsafe water above that level, researchers said.
At present, Bangladesh is the worst-affected country. There, hundreds of thousands or people are likely to die from arsenic poisoning, the researchers said.
Arsenic has also been found in the water in developed countries and industrial activities such as mining can also lead to contamination.
Rising awareness has led to increased testing that has revealed more widespread arsenic in drinking water but other researchers said even more must be done to address the problem.
"Most countries have some water sources with dangerous levels of arsenic, but only now are we beginning to recognise the magnitude of the problem," Allan Smith, a researcher at the University of California, Berkeley and adviser to the WHO on arsenic, said in a statement.
Story by Michael Kahn
REUTERS NEWS SERVICE
World facing 'arsenic timebomb'
By Richard Black, Environment correspondent, BBC News website
30th August 2007
About 140 million people, mainly in developing countries, are being poisoned by arsenic in their drinking water, researchers believe. Speaking at the Royal Geographical Society (RGS) annual meeting in London, scientists said this will lead to higher rates of cancer in the future.
South and East Asia account for more than half of the known cases globally.
Eating large amounts of rice grown in affected areas could also be a health risk, scientists said.
"It's a global problem, present in 70 countries, probably more," said Peter Ravenscroft, a research associate in geography with Cambridge University.
"If you work on drinking water standards used in Europe and North America, then you see that about 140 million people around the world are above those levels and at risk."
Arsenic consumption leads to higher rates of some cancers, including tumours of the lung, bladder and skin, and other lung conditions. Some of these effects show up decades after the first exposure. "In the long term, one in every 10 people with high concentrations of arsenic in their water will die from it," observed Allan Smith from the University of California at Berkeley.
"This is the highest known increase in mortality from any environmental exposure."
The international response, he said, is not what the scale of the problem merits.
"I don't know of one government agency which has given this the priority it deserves," he commented.
The first signs that arsenic-contaminated water might be a major health issue emerged in the 1980s, with the documentation of poisoned communities in Bangladesh and the Indian state of West Bengal.
In order to avoid drinking surface water, which can be contaminated with bacteria causing diarrhoea and other diseases, aid agencies had been promoting the digging of wells, not suspecting that well water would emerge with elevated levels of arsenic. The metal is present naturally in soil, and leaches into groundwater, with bacteria thought to play a role.
Since then, large-scale contamination has been found in other Asian countries such as China, Cambodia and Vietnam, in South America and Africa. It is less of a problem in North America and Europe where most water is provided by utilities. However, some private wells in the UK may not be tested and could present a problem, Mr Ravenscroft said.
Once the threat has been identified, there are remedies, such as as digging deeper wells, purification, and identifying safe surface water supplies.
As a matter of priority, scientists at the RGS meeting said, governments should test all wells in order to assess the threat to communities. "Africa, for example, is probably affected less than other continents, but so little is known that we would recommend widespread testing," said Peter Ravenscroft.
His Cambridge team has developed computer models aimed at predicting which regions might have the highest risks, taking into account factors such as geology and climate.
"We have assessments of the Ganges and Brahmaputra river basins, for example, and then we look for similar basins elsewhere.
"There are similar areas in Indonesia and the Philippines, and very little evidence of tests; yet where there has been some testing, in (the Indonesian province of) Aceh for example, signs of arsenic turned up."
Asian countries use water for agriculture as well as drinking, and this too can be a source of arsenic poisoning.
Rice is usually grown in paddy fields, often flooded with water from the same wells. Arsenic is drawn up into the grains which are used for food.
Andrew Meharg from Aberdeen University has shown that arsenic transfers from soil to rice about 10 times more efficiently than to other grain crops.
This is clearly a problem in countries such as Bangladesh where rice is the staple food, and Professor Meharg believes it could be an issue even in the UK among communities which eat rice frequently. "The average (British) person eats about 10g to 16g of rice per day, but members of the UK Bangladeshi community for example might eat 300g per day," he said.
The UK's Food Standards Agency is currently assessing whether this level of consumption carries any risk.
Six New Orleans Schoolyards Contaminated With Arsenic
NEW ORLEANS, Louisiana, (ENS)
27th August 2007
Six New Orleans schoolyards tested after Hurricane Katrina were found to be contaminated with arsenic in amounts at least double the levels requiring cleanup under both state and federal law, finds a report released today by the Natural Resources Defense Council, NRDC, but state and federal environmental agencies have done nothing to clean them up.
In March, NRDC researchers sampled 116 residential, elementary school, and playground sites in New Orleans.
Results showed that six of the 19 schoolyards tested contained soil that exceeded cleanup guidelines for arsenic established by the Louisiana Department of Environmental Quality, LDEQ, and the U.S. Environmental Protection Agency, EPA. Two playgrounds and four residential areas also .
The schools that tested high in arsenic, in order of high to lower levels of contamination, are - McDonogh Elementary (#42) in the Mid-City area; John Dibert Elementary School in Mid-City; Drew Elementary in Bywater/St.Claude; Craig Elementary in Mid-City; Medard H. Nelson Elementary in the Uptown/Carrollton area; and McMain Magnet Secondary School in Uptown/Carrollton.
On first learning of the test results in June, the NRDC says it immediately informed both state and federal agencies. But with school now back in session, neither agency has taken any measures to protect students.
Both LDEQ and EPA responded to the June warning with letters stating that they are not authorized to move forward on clean-up or a site assessment unless the schools can prove that Hurricane Katrina was the cause of the contaminated sediment.
The NRDC says it has learned that LDEQ recently conducted sampling at four of the six schoolyards with contaminated soil, after the school year began, but the state agency has not made the results of these tests public.
"Families who have chosen to return to rebuild their communities shouldn't have to worry that their children are playing in schoolyards contaminated with cancer-causing chemicals," said Gina Solomon, MD, a senior scientist with NRDC and a co-author of the report. "State and federal agencies are ducking their legal and moral responsibility to the people of New Orleans."
Health experts at NRDC and local groups say the arsenic contamination was left behind in the layers of sediment coating much of the city in the wake of Katrina's flooding.
They say the recommended solution in most cases is to remove and replace the first six inches of contaminated soil. Sampling should also be done at more locations around the city to make sure that other contaminated sites have not been missed, say the national and local environmental groups.
"There is no justification for allowing arsenic to be anywhere near residents or children," said Wilma Subra, a chemist for the Louisiana Environmental Action Network. "Now that we know the film of sediment covering parts of New Orleans contains high levels of arsenic, we need our government to take action and clean it up."
LDEQ officials have argued that the contamination predated the August 29, 2005 storm.
But NRDC says its researchers crosschecked samples from 63 locations in residential areas throughout the city against samples collected before the storm, and confirmed that before Katrina, arsenic was not a problem in most of them.
"There is strong evidence to prove Hurricane Katrina exacerbated arsenic levels throughout the city," said Al Huang, environmental justice attorney for NRDC, and a co-author of the report. "Regardless of the cause, there are children being exposed to arsenic today, and it is the duty of our government to right that wrong."
The arsenic found in this sediment could have originated from multiple sources, including the accumulation of arsenic-based pesticides displaced from the bottom of Lake Pontchartrain, trash incineration, leakage from industrial sites, or lumber treated with chromium-copper arsenate.
Since Katrina, neither the LDEQ nor the EPA has conducted a cleanup of contaminated sediment.
Arsenic is toxic to humans, and is known to cause cancer, birth defects, cardiovascular disease and neurological disorders. No amount of arsenic exposure is considered fully safe.
Soil contaminated with arsenic can be inhaled when the dirt is moved. It can also enter the body through the eyes or mouth. Children are particularly vulnerable.
"The testing shows that our children are being exposed to dangerously high levels of arsenic," said Beverly Wright, Director of Deep South Center for Environmental Justice.
"It is the government's responsibility to provide clean and healthy schools for our children, and it is their duty and moral obligation to help this city get back on its feet," Wright said. "In the meantime, community-based projects will continue to do the hard work of cleaning up our own neighborhoods block-by-block."
The report was prepared by NRDC's experts on health and environmental justice and is available online.
Copyright Environment News Service (ENS) 2007.
Miércoles 29 de Agosto, 2007
Por Michael Kahn
LONDRES (Reuters) - La aparición normal de arsénico en agua potable genera un creciente riesgo global para la salud, mientras grandes números de personas consumen sin saberlo niveles poco saludables del elemento químico, dijeron el miércoles investigadores.
El problema es mayor de lo que pensaban los científicos y afecta a casi 140 millones de personas en más de 70 países, de acuerdo a una nueva investigación presentada en la reunión anual de la Sociedad Geográfica Real en Londres.
El arsénico puede causar enfermedades pulmonares y cáncer, inclusive después de dejar de tomar agua contaminada, dijo Peter Ravenscroft, investigador de la Universidad de Cambridge.
"Lo nuevo es que el nivel de contaminación con arsénico es mucho mayor del que la gente cree," dijo Ravenscroft en una entrevista telefónica.
"Hay una conexión muy importante entre el arsénico en agua y el arsénico en comida, especialmente donde la gente tiene cultivos irrigados," agregó.
Los parámetros de la Organización Mundial de la Salud indican que 10 partes por mil millones de arsénico en suministros de agua es un límite seguro, pero decenas de millones de personas en el mundo toman agua insegura por encima de ese nivel, dijeron los investigadores.
Actualmente, Bangladesh es el país más afectado. Allí existe la probabilidad de que cientos de miles de personas mueran por envenenamiento con arsénico, dijeron los investigadores. También se ha encontrado arsénico en aguas de países desarrollados y actividades industriales como la minería también pueden provocar la contaminación.
La concientización sobre el tema condujo a más pruebas, que revelaron la presencia generalizada de arsénico en agua potable, pero otros investigadores dijeron que aún se deben hacer más cosas para abordar el problema.
"La mayoría de los países tienen algunas fuentes de agua con niveles peligrosos de arsénico, pero recién ahora estamos comenzando a reconocer la magnitud del problema," dijo Allan Smith, investigador de la Universidad de Berkeley, California, y asesor de la OMS sobre el químico, en un comunicado.