Scourge of arsenic
Arsenic is a toxic constituent that can contaminate water, land, crops and the overall environment, finally affecting human health and welfare. It occurs in nature in diverse minerals. Natural phenomena, collectively with human performance, are accountable for its discharge into the atmosphere, soil and water. Individual exposure risks are mainly restrained to regions where pollution of natural possessions such as water, soil, and air is occurring. There are two major ways in which humans are exposed to arsenic. First, directly through arsenic-laden water that people drink; and secondly indirectly, through food crops grown on soils polluted by long-term irrigation with arsenic-rich irrigate. Arsenic may also affect animals if they are fed with high-arsenic straw, which can be an additional indirect hazard for humans. The most dangerous aspect for humans is the release of arsenic into underground water from sediments through natural chemical and biochemical processes like the oxidation of arsenic-rich sulphide compounds and the reduction of arsenic containing iron oxides.
Arsenic cannot be smashed in the environment; it can only change its form and location of accumulation. For instance, rain and snow remove arsenic dust particles from the air, but it then accumulates in the soils, becoming a threat to crops. Arsenic can be easily removed from drinking water by treating the water with iron compounds, but the waste disposal would contaminate the soils. Some plants, such as ferns, can absorb large amounts of arsenic from the soils, but the poison returns to the soil through recycling of the plant residues. Arsenic is naturally removed from human and animal bodies through excreta, but the arsenic so released ultimately ends up in the soil or water.
Irrigation with arsenic-contaminated groundwater leads to elevated levels of arsenic in soils, which may lead to increased concentration of arsenic in plants. Ingesting very high levels of arsenic can result in death. Arsenic causes acute and chronic adverse health effects, including cancer and lower levels can cause nausea and vomiting, decreased production of red and white blood cells, abnormal heart rhythm, damage to blood vessels, and the sensation of "pins and needles" in hands and feet. Breathing high levels of inorganic arsenic can lead to sore throat or irritated lungs.
To diminish risk of exposure farmers should wear trousers to avoid direct contact with high-arsenic mud in the fields. Caution should also be taken while handling pesticides. Safe levels of arsenic in drinking water according to the World Health Organization's safety level is 0.01 mg/L maximum and should be ensured through the use of safe water sources.