Introduction to Arsenic

Arsenic in Water, Agriculture, and the Environment
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Arsenic and Human Health

The detrimental effects of arsenic on human health can be divided into two broad categories:

Chronic (non-cancerous) adverse effects:
I. Melanosis:
After a few years of continued drinking of arsenic contaminated water, visible symptoms on the skin might begin to appear, i.e., hyperpigmentation (dark spots) or hypopigmentation (light spots). The first symptoms often occur on the palm of the hand. The affected area is initially smooth to the touch. These symptoms are collectively known as melanosis. The occurrence and time from initial arsenic exposure to development of visible symptoms are highly impacted by the arsenic exposure level and the general health and nutrition of the individual.
Whole body melanosis
Whole body melanosis

II. Keratosis:
Arsenical keratoses are usually multiple and typically occur at sites of friction and trauma, especially on the palms and soles. Keratoses may also develop on the fingers, the toes, the heels, the dorsum of the hands, the arms, and the legs. Keratoses usually occur as small, punctate, non tender, hard, yellowish, often symmetric, corn like papules.
Keratosis on feet

III. Gastrointestinal, Hepatic and Renal effects

IV. Cardiovascular effects

V. Neurological effects

Cancer effects

Squamous cell carcinoma on hands
Squamous cell carcinoma on head
  • Skin cancer
  • Urinary, bladder cancer
  • Lung cancer
  • Liver and kidney problems associated with arsenic induced skin cancers

Arsenic can also result in a general deterioration in health, which can negatively impact a person's ability to support and care for their family.

Factors Influencing Occurrence and Severity of Human Health problems

A dose-response relationship exists between the arsenic exposure level and the frequency of different skin symptoms. Five major categories of sources from which patients might have been exposed to arsenic include medicinal, drinking water, inhalation, food, and occupational hazards.  A person's dose-response relationship is also influenced by general health and nutrition. In Bangladesh the major source of arsenic exposure is drinking water, followed to a lower extent by food. The contribution of inhalation is not known.