Top Six Toxic Threats for world in the report of Blacksmith Institute

[hafiz ishtiaq ahmad]

The six pollutants profiled in this report were selected on the basis of the number of people that Blacksmith Institute estimates are at risk from sites impacted by these contaminants. The population estimates are based on the research conducted by field investigators as part of our ongoing effort to identify and evaluate polluted sites in low- and middle-income countries.

1. Lead:
Lead is a naturally occurring heavy metal and a powerful neurotoxin. Lead is often released during metal smelting and mining, and is a key component in car batteries. Lead can exist in air, water, soil, and food and can enter the human body through inhalation, ingestion or dermal contact. The health effects of lead exposure can include neurological damage, reduced IQ, anemia, nerve disorders, and a number of other health problems. The effects of lead are most severe in children, and at high concentrations, lead poisoning can cause death. Learn More

2. Mercury:
Metallic mercury, the elemental or pure form, is a silver-white metal that is liquid at room temperature and commonly seen in thermometers. Mercury is often used in the production of chlorine gas, caustic soda, batteries, and electrical switches, and is also used to extract gold from ore. A person can be exposed to mercury through air, water, food, or dermal contact. Mercury is a powerful neurotoxin and can cause severe damage to the brain and kidneys. Inhalation of mercury can also cause lung, stomach, and intestinal damage, and even death due to respiratory failure. Learn More

3. Chromium:
Chromium is a naturally occurring heavy metal that is commonly used in industrial processes. Although it can be released through natural forces, the majority of the environmental releases of chromium are from industrial sources. The industries with the largest contribution to chromium levels include leather tanning operations, metal processing, stainless steel welding, chromate production, and chrome pigment production. Chromium can exist in air, water, soil, and food, and common exposure pathways include ingestion, inhalation, and dermal contact. The primary health impacts from chromium are damage to the gastrointestinal, respiratory, and immunological systems, as well as reproductive and developmental problems. Chromium is a known human carcinogen. Learn More

4. Arsenic:
Arsenic is a naturally occurring element that is frequently characterized as a metal, despite having properties of both a metal and a nonmetal. Arsenic is often found in rocks that contain other valuable metals, such as copper and lead. When smelters heat this ore to retrieve the other metals, the arsenic can be released into the air. Arsenic can exist in air, water, soil, or food, and all of these present potential pathways for human exposure. Arsenic has long been recognized as a poison, and large oral doses can cause death. Lower doses of arsenic can cause decreased production of red and white blood cells, and arsenic poisoning is often characterized by visible changes in the skin. Arsenic contamation of ground water is a significant problem in South Asia. Learn More

5. Pesticides:
Pesticides are those substances, often chemical in nature, that are used with the intent to repel or eliminate species that have an adverse effect on agricultural or horticultural production. Pesticides are also used to fight tropical diseases like malaria. A “pesticide” can be classified as an insecticide, herbicide, fungicide, nematocide, and molluscicide. A significant volume of the pesticides used each year is washed away by rainfall into nearby surface and ground water, and water is a common exposure pathway. Studies on chronic health effects of pesticide exposure indicate the potential for these chemicals to have neurological, reproductive, and dermatological impacts. Learn More

6. Radionuclides:
Radionuclides occur naturally in soil and rocks as a consequence of radioactive decay. While they can be released through natural cycles, most environmental releases are the consequence of industrial processes. Common sources of radionuclide exposure include uranium mining and mine waste dumps, nuclear weapons production and testing, processes related to nuclear energy production, and the production of radiological products for medical use. When radiation strikes a living organism’s cells, it can damage those cells. If radiation affects a significant number of cells, the organism may eventually develop cancer, and at high doses, radiation can cause death