Inorganic arsenic compounds: are they carcinogenic, mutagenic, teratogenic?

Area of Science:

• Environmental Health
• Toxicology
• Carcinogenesis

Background:

• Inorganic arsenic compounds are prevalent environmental contaminants.
• Occupational and environmental exposures have raised concerns about arsenic's health effects.

Purpose of the Study:

• To review and evaluate the existing literature on the carcinogenicity of inorganic arsenic compounds in humans and laboratory animals.
• To assess the epidemiological evidence and mechanistic understanding of arsenic-induced cancers.

Main Methods:

• Systematic review of epidemiological studies on occupational and environmental arsenic exposure.
• Analysis of toxicological data from animal studies.
• Evaluation of dose-response relationships and observed cancer types.

Main Results:

• Convincing epidemiological evidence links inorganic arsenic exposure to human cancers, particularly of the lungs, skin, and gastrointestinal tract.
• Positive dose-response relationships were observed in various exposure scenarios.
• Inorganic arsenic compounds demonstrated limited carcinogenicity in laboratory animals across most administration routes.

Conclusions:

• Inorganic arsenic is a proven human carcinogen, despite a lack of consistent carcinogenicity in animal models.
• The mechanisms underlying arsenic carcinogenicity in humans remain largely unknown.
• Further animal studies, particularly using intratracheal administration, are recommended to elucidate carcinogenic pathways.