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Facing up to “invisible pollution”

Soil contamination has grown unnoticed across China’s landscape. Now, reports Xu Qi, a major geochemical survey is under way, designed to diagnose the extent and severity of the problem.

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Food safety is a basic need for any population, yet we hear warnings of hidden dangers on the dining-room table – of unsafe rice and poisoned vegetables. With the launch of the China Soil Survey, pollution of our soil is now receiving the kind of attention once accorded to air and water, solid waste and noise.

Soil pollution has been called the “invisible pollution.” While other forms of pollution have obvious warning signs – visible contamination of a river, for example, or an airborne stench – soil pollution is easier to miss. And so this grave threat has been growing unnoticed in our fields.

In some areas of China, soil already suffers from varying degrees of pollution. According to the State Environmental Protection Administration (SEPA), the situation is worsening and already represents a threat to the environment, to food safety and to sustainable agriculture. According to a scientific sampling, 150 million mu (100,000 square kilometres) of China’s cultivated land have been polluted, with contaminated water being used to irrigate a further 32.5 million mu (21,670 square kilometres) and another 2 million mu (1,300 square kilometres) covered or destroyed by solid waste. In total, the area accounts for one-tenth of China’s cultivatable land, and is mostly in economically developed areas.

Soil pollution presents a genuine danger. An estimated 12 million tonnes of grain are contaminated by heavy metals every year, causing direct losses of 20 billion yuan (US$2.57 billion). Harmful substances accumulate in crops and, via the food chain, find their way into our bodies, where they can cause a variety of illnesses. Soil pollution also damages ecosystems and ultimately threatens their safety.

Measures to prevent soil pollution are weak in China. Currently, given the amount of land in question, the degree of the pollution in specific locations is unclear, making both prevention and remedy difficult. There are no laws or environmental standards regarding soil. Funding is limited, too, so there is little advanced scientific study of China’s soil taking place. The severity of the pollution is not understood by either the public or business, and the situation is worsening.

More worryingly, treating soil pollution – especially that caused by heavy metals – is costly, and such contamination is difficult to eliminate completely. According to Liu Xiaoduan, a specialist at China’s National Research Centre for Geoanalysis (NRCGA), heavy metals are naturally widespread in the soil and cannot be removed. But they can form organic compounds or build in some organisms, and thus end up in the human body, where they accumulate.

“Some time ago, the focus of our work shifted from prospecting for ore, and we now have a number of different aims,” says an official with the China Geological Survey’s department of geological investigation. The aim of agricultural security grew from ensuring quantity to ensuring safety; soil management has become about quality rather than quantity, and environmental awareness is ever increasing. Geochemistry is playing a greater role in both the economy and society.

The science and technology behind prospecting for ore is now the basis for environmental geochemistry, which includes the earth’s atmosphere and hydrosphere, ecosystems and geology – allowing China to carry out detailed and precise soil surveys. It allows geochemistry to play a role in studies of the environment, agriculture, soil quality, oceans and prospecting, and also helps scientists to develop geochemical theory and new technology.

Lu Anhuai, of Peking University’s school of earth and space sciences, says that surveys have found regional geochemical abnormalities which impact upon the environment of cities and villages, and even upon China as a whole. The survey group proposed a number of economic measures to help protect the environment, which were given serious consideration by the government. Surveys of 21 provinces found localised geochemical issues, such as areas of high disease incidence, and various environmental problems in areas which produce particular crops or which surround mines.

China previously carried out two national soil surveys, in the late 1950s and in the ’70s. Both studies focused on soil fertility and agricultural productivity, rather than soil pollution. However, the aim of the latest government-funded appraisal -- costing 1 billion yuan (US$128.6 million) -- is to study the overall state of China’s soil in a comprehensive, systematic and accurate manner. It is intended to: identify the type, degree and cause of soil-pollution hotspots; evaluate associated risks; set environmental classifications for soil; select and trial soil-recovery technology; put together a system of laws and standards regarding soil pollution; and improve environmental management of soil.

Due to conclude in 2008, the survey will focus on protected farmland and grain production areas. The soil-pollution survey will focus on the Yangtze and Pearl River basins, the area surrounding the Bohai Gulf, the former heavy-industrial areas of the north-east, the plains of Sichuan and Shanxi, and major mining cities. The formation of a system to oversee soil environmental quality will focus on improving testing ability and drafting soil pollution laws.

The Geological Survey bureau says three million square kilometres of soil in the Yangtze and Yellow River basins, the plains of the northeast, developed coastal areas and the west of China. One million square kilometres have been surveyed already; and a further one million will be examined in the time of the 11th Five Year Plan, which runs to 2010. Completion is due in the period of the 12th Five Year Plan. Regional situations will be summarised and a “National Geochemical Map” produced, which will finally allow us to fully grasp the truth of soil pollution in China.

This article was adapted from China Environmental Times, December 28, 2006.

Qi Xu is a journalist for China Environmental Times.

Homepage photo by Ari Moore

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匿名 | Anonymous



Farmers are the victims of soil contamination

Farmers are the major victims of soil contamination. China should build a mechanism to make sure the polluters compensate peasants for their affected farmlands.

Default avatar
匿名 | Anonymous


什么是造成土壤污染的主要根源? 是储存在空气中的颗粒、灌溉用水、工业废弃物、杀虫剂或者是化肥的污染所造成的呢?对目前正在建设中的中国,偶尔在操作废水处理的工作以改善河流素质的当时也制造了“生物土” (污泥)。从理想上来说,这些污泥应该传布在土壤中成为有机肥和土壤调节剂, 然而,还必须非常谨慎而不至于成为污染土壤的根源。为了预防类似土壤污染的发生,废水处理公司在进行工作时必须负起责任,了解污泥的质量所将带来的影响和管制废水中有毒物质的排放。对目前的情况而言,如果在这一方面缺乏相应的措施,土壤污染的情况即将显著的加剧。S Spooner, 英国/ 北京

Sources of pollution?

What are the main sources of soil pollution? - Airbourne deposition, irrigation water, industrial waste, pesticides and contaminated fertilisers?

As China gradually constructs, and sometimes operates, wastewater treatment works to improve the quality of rivers so biosolids (sludge) will be produced. Ideally this should be spread on land as an organic fertiliser and soil conditioner, however great care will be required to ensure that this does not become a further source of soil contamination.

Preventing such pollution will require waste water companies to have a responsibility for sludge quality and powers to know about and control toxic discharges to the sewers that run to their works.

Without such measures, and they do not generally exist at present, the story of soil contamination will become dramatically worse.

S Spooner, UK / Beijing

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匿名 | Anonymous



Soil pollution is as severely as water pollution

Soil pollution is related closely with human's life safty as water pollution to be,with the same importance and grimness.In the field of water pollution,people realised as there was Ma Jun's .However to the soil pollution,it don't be given enough attention,so here to hope that someone show the problem profoundly soon.

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匿名 | Anonymous



The origin and spread of soil pollution

Let me add briefly by introducing what I know about soil pollution. Soil pollution can be divided into two parts: living and non-living. The living part, largely, refers to bacteria in the soil, tiny harmful lifeforms, and pests. For example, in the past, for a lot of tapeworms, schistosomes in pork meat etc., soil has been one of the key links to their growth. With the raising of the hygiene level, this kind of harmful material gradually works its way into people's attention. The non-living part can be further divided into two subcategories, organic and inorganic. Organic pollution is that created by people, such as benzopyrene etc., which degrades with difficulty, just like plastic. Yet there are things even more toxic to living beings, and they come in all shapes and sizes, so that it is hard to predict how toxic it might turn out to be. The inorganic is that released by people, and soil for the most part consists of things that are fundamentally harmless for people, even if the little part left over has toxic elements. Because the density is very low, it is very difficult for it to cause harm. Through mining activities, we release all kinds of underground metals from the ground, they enter into the daily lives of people and are deposited on the surface of the earth. As soon as their density passes a safe level, it constitutes pollution. In the future, because of this, perhaps there will appear this kind of scene: in places that have cities and mines as their centres, there will be a proliferation of metals and clean soil will no longer exist. The scariest thing is that this kind of pollution, once poured out like this into water, can no longer be recovered. This is unlike organic pollution, where time is needed, and with the use of non-living and living things, one day it will disappear. The disappearance of metal pollution in the soil will come as the surface of the planet moves underground, unless the earth itself instigates extremely strong crustal movement. Finally, one day, we will have no choice but to use again, to recycle, all the water we have poured out. With some difficulty, you can just imagine this.

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匿名 | Anonymous



Great work!

Hello!I enjoyed looking around Your web-site!Keep up this great resourse!With the best regards!

Default avatar
匿名 | Anonymous



well done

well done ! from it i found a lot of informations^^

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匿名 | Anonymous



good job

i find many imformation here

Default avatar
匿名 | Anonymous



good idea

Thank you for giving me a so good way to find information about pollution.

Default avatar
匿名 | Anonymous



Good work

It can be better soon.

Default avatar
匿名 | Anonymous




Invisible pollution

Food safety is a basic need for any population, yet we hear warnings of hidden dangers on the dining-room table – of unsafe rice and poisoned vegetables. With the launch of the China Soil Survey, pollution of our soil is now receiving the kind of attention once accorded to air and water, solid waste and noise.

Soil pollution has been called the “invisible pollution.” While other forms of pollution have obvious warning signs – visible contamination of a river, for example, or an airborne stench – soil pollution is easier to miss. And so this grave threat has been growing unnoticed in our fields