Inorganic Arsenic and its Effect on the Health of Humans and on the Environment

Arsenic is found at Low Levels in Many Foods

Arsenic is a chemical element occurring naturally in the earth’s crust and throughout the environment. It is found in small quantities in soil, rocks, air and water. It enters human beings primarily through food containing arsenic. Small quantities can be absorbed through the skin and by the way of inhalation. It can enter groundwater through erosion. It is used in the manufacturing of multiple goods and can enter the soil and water through industrial effluents. Arsenic can exist in two different chemical forms- organic and inorganic. While organic arsenic is non toxic, inorganic arsenic can give rise to many diseases including cancer.

Arsenic is present at low levels in many foods like poultry, meat, vegetables, fruits, cereals, milk and dairy products. Large quantities of organic arsenic tend to get accumulated in fish and sea food. According to a study, seafood other than fish is the main source of arsenic exposure (51%) followed by fish (26%), cereals and its products (10%), vegetables (6%), meat and poultry products (4%) and milk and dairy products (3%).

According to The Joint FAO/WHO Expert Committee on Food Additives (JECFA), a provisional tolerable weekly intake (PTWI) of inorganic arsenic is 15 micrograms/kg/week. Levels beyond it can be detrimental to health.

Ill Effects of Arsenic on Human Health and Environment

Inorganic arsenic is a known carcinogen. Its teratogenic effects include cleft palate, neural tube defects and delayed hardening of bones in infants. Lung cancer can result due to inhalation of inorganic arsenic while ingestion of food and water contaminated with inorganic arsenic can lead to bladder, liver, kidney, prostate and skin cancers. Ingesting small amounts of arsenic over a period of time can lead to damage to peripheral nerves, skin hyper pigmentation, hair and appetite loss and effects on the cardiovascular system. It can lead to preterm delivery, miscarriages, low birth weight and high infant mortality. In children, exposure to inorganic arsenic has been associated with a decrease in IQ and long term memory. Acute exposure to inorganic arsenic can lead to nausea, vomiting and abdominal pain besides neurological symptoms like headaches and dizziness. Chronic exposure to inorganic arsenic has also been linked to the development of diabetes.

Inorganic arsenic poses danger to the environment as well. It contaminates the surface and ground water. The chicken litter containing arsenic which has been used as a fertilizer can contaminate the soil. The bacteria present in the soil can accelerate the conversion of organic arsenic into toxic inorganic arsenic, according to Duquesne study by John Stolz, a professor of Biology and Partha Basu, an environment chemist. The conversion takes place in less than a week.

Arsenic is also produced as a by-product of power plants burning coal and by other industries like copper smelting and mining. The addition of arsenic to the environment by these industries is closely monitored and its use in pesticides and as a preservative in pressure treated wood has been banned. The U.S. Environmental Protection Agency is reconsidering its approval of organic applications to control the growth of weeds on the golf courses.

Taking into consideration the host of environmental and health problems that inorganic arsenic poses, its use in chicken feeds is controversial and should be completely banned.