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The Remaining Five Sources



The Remaining Five Sources


The following list of sources contains industries that Blacksmith believes contribute significantly to toxic pollution problems, but are either unquantifiable because of lack of data, or represent a smaller impact than the above top ten list.

Petrochemicals are chemical products derived from petroleum or other fossil fuels. Petrochemicals refer to a wide array of chemicals and could include chemicals discussed earlier in this report. They are chemicals that are used in adhesives, carpeting, cosmetics, paint, rubber, fabrics, fertilizers and plastics. Petrochemical processing is especially unique because fossil fuels such as oil and natural gas are used to create the building blocks of these chemicals. Because of this, petrochemical processing is often done in oil producing regions and occurs alongside other oil refining processes.

Pollution from oil use and production is generally outside of the scope of Blacksmith Institute’s work, due to the globally pervasive nature of this industry and number of sites impacted by oil pollution. Inclusion of this industry within our work would overwhelm current resources and lead to poorer understanding of the impact of other industries. The petrochemical industry is the exception.

Pollution from petrochemical processing and production contributes to 75 sites in the Blacksmith Institute’s database, potentially exposing more than 2.2 million people to pollution from petrochemical processing sites. Blacksmith has investigated polluted petrochemical sites in Africa, South America, Eastern Europe and South Asia. The petrochemical sites in the Blacksmith industry are largely polluted by untreated wastewater and sludge being disposed of in surface water sites. Untreated waste from petrochemical sites can contain very toxic pollutants and is tightly regulated in developed countries. The majority of investigated sites are contaminated by lead, but a large array of chemicals is found. These include, cadmium, mercury, volatile organic compounds, PCBs and oil or petroleum products. Health impacts from these sites include neurological damage, lung irritation and disease and forms of cancer.

E-waste is the general term for electronic waste from discarded computers and printers, cell phones, televisions and other related consumer products. Consumer demand drives the technological innovation that creates a cycle of obsolescence in which new devises are turned over almost yearly. This constant stream of new products results in an urgent and complex waste problem, it is estimated that 500 million computers became obsolete in the U.S. between 1997 and 2007, and computers represent only a small percentage of e-waste.[1] Total global e-waste estimates number between 20 and 50 million tons annually.[2] The waste is rarely processed in developed countries; an estimated 70 percent of it is imported to China.[3] In the Blacksmith Institute’s database there are almost 50 sites polluted by e-waste, potentially putting close to 600,000 people at risk. Of the 50 sites, majorities are located in China with Africa and South America holding several sites as well.

E-waste is made up of a mixture of different materials. Its complicated make up of metals, chemicals and plastics make it a unique stream of waste that requires specialized solutions. Many of the components contain a mix of heavy metals, and chemicals like PCBs and brominated flame-retardants.[4] The waste must be dismantled and the components extracted before recycling or disposal can take place. Many of the methods used, even in formal e-waste disposal sites, are unsafe and release hazardous elements. Recycling operations observed in developing countries have exposed open burning and dismantling of waste, cracking of cathode ray tubes containing high levels of lead, and unsafe dumping of waste products.[5] These processes release large amounts of toxins into the air where they are inhaled by e-waste workers and settle on the surrounding environment. Pollutants found in polluted e-waste sites from the Blacksmith Institute’s database include lead, chromium, cadmium, and polychlorinated biphenyls or PCBs. These pollutants cause neurological damage, lung irritation and disease and forms of cancer.

Increasingly, countries like China and India are creating laws to regulate the flow of e-waste imports; however there is still a vast market of illegal e-waste dumping and processing that is outside the realm of regulation. The Basel Ban forbids the export of e-waste to developing countries, but often e-waste is sent to low-income countries under the guise of donations. Recently countries in Africa, like Ghana and Nigeria, have come under a deluge of e-waste through a loophole that allows electronic goods to be exported as ‘working products’. When the “donations” are received, often times few of the items are even functioning, half a million PCs arrive in Lagos every month, and only 1 in 4 work. [6] The waste is usually burned to recover some of the materials or dumped, as the countries have no infrastructure to support recycling.

Heavy industry refers to metal casting, stamping or rolling production processes that create very large sized and heavy metal parts. These parts are usually designed and created for use in other large industrial processes such as electric plants and automotive plants. The industry processes varies greatly depending on the material used and type of product produced. Possible materials include steel, iron, brass or aluminum. It is a multi-step process that features many different chemical additives, heating and melting of elements and large amounts of water. Chemical additives include but are not limited to benzene, formaldehyde, toluene, cyanide salts and hydrofluoric acid.[7]

Most large heavy industry plants in developed countries are now closely regulated and their emissions and pollutants are monitored. There are advanced pollution controls and waste treatment options for the industry. Despite this, there are over 70 polluted heavy industry sites in the Blacksmith Institute’s database, potentially putting almost 3 million people at risk. The majorities of polluted heavy industry sites in the Blacksmith Institute’s database are abandoned sites or are small-scale plants that are unlicensed, lacking controls and have little resources to invest in new technologies or controls. The sites are geographically widespread with China, Eastern Europe, South and Southeast Asia having a large percentage of pollution incidences from heavy industry.

The key pollutants present at heavy industry sites include chromium, cyanide, cadmium, arsenic, and VOCs. Lead is the top pollutant at these sites, contributing the most to the global burden of disease and affecting the largest population. Pollutants from heavy industry enter the environment through contaminated wastewater and air that affects soil, food and drinking water for the surrounding communities. Health effects from these potential exposures include neurological damage, lung cancer, leukemia and other lesser effects.

Pesticide is an umbrella term used for any substances that prevent or destroy pests and it includes insecticides, herbicides and bactericides. They are important components of our agricultural system since roughly one-third of agricultural crops are produced with pesticides.[8] In addition, pesticides like DDT are used to combat the spread of malaria through mosquitos. Pesticides are chemical compounds with an active ingredient, that are then mixed with other chemicals to produce specific effects or to suit the delivery method intended.[9] During manufacturing pollutants can be created from the reaction, from the filtering and purification systems, and from drying and extraction activities.[10]

Polluted pesticide manufacturing and storage sites and sites contaminated by agricultural practices investigated by the Blacksmith Institute potentially put close to 8 million people at risk at nearly 200 sites in the developing world. Pesticides are widely used throughout the world; key problem regions in the Blacksmith Institute’s database include Eastern Europe, Central and South America and South Asia; China has become the largest pesticide producer and exporter in the world.[11]

Decaying storage facilities, waste from manufacturing processes and agricultural applications cause the majority of pesticide pollution. Over 4.6 million tons of pesticides, made up of 500 different types, are sprayed on crops annually.[12] When sprayed, only 1% of pesticides end up being effectively utilized, in most instances they are distributed into the air and water.[13] Surrounding communities directly consume pesticides through inhaling of contaminated air, ingesting or bathing in contaminated waters and ingesting food unknowingly covered with pesticides. When crops are irrigated the water picks up pesticides and carries them to surrounding waterways via runoff. The breadth and reach of dispersed pesticides is alarming: studies have detected levels of DDT, lindane and aldrin in tree bark at the equator and in Greenland ice sheets and Antarctic penguins.[14]

Blacksmith previously sited pesticides as a top pollution problem, while this remains true, health impacts from exposure to pesticides are difficult to quantify. There are many and varied forms of pesticides, some are more hazardous than others and there is a limited understanding of the health impacts of some pesticides. As an example of toxic pesticides, lindane and DDT are found frequently in polluted sites in the Blacksmith Institute’s database and both are toxic to the liver and lindane is toxic to kidneys. DDT has also been defined as a probable carcinogenic in high doses and lindane as a possible carcinogenic for its link through animal studies to liver cancer. However, DDT in lower doses has not been proven to cause cancer and is still used to combat mosquitos in developing countries because of the overwhelming positive upside to reducing the incidence of malaria.

The technology and resources are available to remediate legacy pesticide storage sites and prevent exposure from manufacturing processes. Education and investment in newer manufacturing technologies could help prevent many instances of pollution. Currently, there are several international agreements and treaties that advance the safe management of pesticides. For example, the U.S., EU and 90 other countries signed the Stockholm Convention on Persistent Organic Pollutants, a UN treaty, in May 2001. The Stockholm Convention compels countries to reduce or prohibit production, use or release of 12 persistent organic pollutants, including several pesticides such as aldrin and DDT. In 2009, nine additional pollutants were added to the agreement, including the pesticide lindane.[15] These type of international agreements help reduce human exposure to toxic pollutants and help countries safely manage chemicals.

Uranium processing for the purpose of creating nuclear energy is a complex, multistep process that includes the mining, processing, and refining of uranium ores, which then undergo enrichment processes. The problem with uranium processing is the amount and toxicity of the waste created. However, the very complex questions of spent nuclear waste disposal are beyond the scope of Blacksmith.

There is only a small number of nuclear fuel processing sites in the Blacksmith Institute’s database, however these sites potentially put more than 1.3 million people at risk for severe health impacts. The majority of the sites are in Eastern Europe, the bulk of them located in Russia. Half of the sites are still in operation, while the other sites are legacy pollution sites that have been abandoned. Radionuclides such as uranium and cesium are the major pollutants at these sites. At the legacy pollution sites, radioactive waste was often disposed of directly into surrounding waterways, with no treatment or processing. At other sites, unintended spills or accidents released radioactive waste into the environment. Radionuclides are found in the water, soil and food chain of these contaminated areas and many serious health effects have been observed. In addition to fuel processing, mining of uranium in low- and middle-income countries frequently contributes toxic pollutants to the environment, as discussed in the mining and ore processing section of this report.

Radionuclides are naturally occurring elements that are radioactive, meaning that they have atoms with unstable nuclei. As elements or materials decay, they will emit radiation up to an end point in the decay process. Some materials decay quickly, but some, like uranium, can continue to be radioactive for millions of years. During the decay, different levels of radioactivity with different health effects can be generated. Uranium radionuclides can cause damage to kidneys and to the genetic code, which can often impact fetal development. Other radionuclides, such as radon, can lead to leukemia and decreases in white blood cell counts.




[1] Zeng, H.N.E. “Law Enforcement and Global Collaboration are the Keys to Containing E-Waste Tsunami in China.” Environ. Sci. Technol. 43, 3991–3994. 2009
[2] “E-waste pollution threat to human health.” Institute of Physics. May 31, 2011. Available at:
[3] Zeng, H.N.E. “Law Enforcement and Global Collaboration are the Keys to Containing E-Waste Tsunami in China”. Environ. Sci. Technol. [4], 3991–3994. 2009
[5] Zeng, H.N.E. “Law Enforcement and Global Collaboration are the Keys to Containing E-Waste Tsunami in China”. Environ. Sci. Technol. 43, 3991–3994. 2009
[6] Ibid.
[6] “The Real Deal: E-waste: West Africa continues to drown in the rich world’s obsolete electronics.” Consumers International. April 2008
[7] “Guides to Pollution Prevention: Metal Casting and Heat Treating Industry.” U.S. Environmental Protection Agency. Washington, DC. 1992. Available at:
[8] Zhan, W., et al. “Global pesticide consumption and pollution: with China as a focus.” Proceedings of the International Academy of Ecology and Environmental Sciences. 1(2):125-144. 2011.
[9] “Pesticide Industry: A Profile – Draft Report.” Research Triangle Institute. Prepared for the U.S. Environmental Protection Agency, December 1993. Available at:
[10] “Environmental, Health, and Safety Guidelines for Pesticide Manufacturing, Formulation and Packaging.” The World Bank Group. Washington, DC. April 2007. Available at:,+Health,+and+Safety+Guidelines/
[11] Zhan, W., et al. “Global pesticide consumption and pollution: with China as a focus.” Proceedings of the International Academy of Ecology and Environmental Sciences. 1(2):125-144. 2011.
[12] Zhan, W., et al. “Global pesticide consumption and pollution: with China as a focus.” Proceedings of the International Academy of Ecology and Environmental Sciences. 1(2):125-144. 2011.
[13] Ibid.
[14] Ibid.
[15] More information available at: Stockholm Convention Homepage at