Title: Arsenic poisoning - Wikipedia
Headings: Arsenic poisoning
Arsenic poisoning
Contents
Signs and symptoms
Cancer
Causes
Drinking water
Groundwater
Food
Soil
Air
Pesticides
Copper smelting
Pathophysiology
Mechanism
Kinetics
Heat shock response
Oxidative stress
Diagnosis
Treatment
Chelation
Nutrition
History
Legislation
Challenges to implementation
Pregnancy
See also
References
Further reading
External links

Content: Cancer
Arsenic increases the risk of cancer. Exposure is related to skin, lung, liver, and kidney cancer among others. Its comutagenic effects may be explained by interference with base and nucleotide excision repair, eventually through interaction with zinc finger structures. Dimethylarsinic acid, DMA (V), caused DNA single strand breaks resulting from inhibition of repair enzymes at levels of 5 to 100 mM in human epithelial type II cells. MMA (III) and DMA (III) were also shown to be directly genotoxic by effectuating scissions in supercoiled ΦX174 DNA. Increased arsenic exposure is associated with an increased frequency of chromosomal aberrations, micronuclei and sister-chromatid exchanges. An explanation for chromosomal aberrations is the sensitivity of the protein tubulin and the mitotic spindle to arsenic. Histological observations confirm effects on cellular integrity, shape and locomotion. DMA (III) is able to form reactive oxygen species (ROS) by reaction with molecular oxygen. Resulting metabolites are the dimethylarsenic radical and the dimethylarsenic peroxyl radical.