Arsenic: health effects, mechanisms of actions, and research issues.

Abstract

A meeting on the health effects of arsenic (As), its modes of action, and areas in need of future research was held in Hunt Valley, Maryland, on 22-24 September 1997. Exposure to As in drinking water has been associated with the development of skin and internal cancers and noncarcinogenic effects such as diabetes, peripheral neuropathy, and cardiovascular diseases. There is little data on specific mechanism(s) of action for As, but a great deal of information on possible modes of action. Although arsenite [As(III)] can inhibit more than 200 enzymes, events underlying the induction of the noncarcinogenic effects of As are not understood. With respect to carcinogenicity, As can affect DNA repair, methylation of DNA, and increase radical formation and activation of the protooncogene c-myc, but none of these potential pathways have widespread acceptance as the principal etiologic event. In addition, there are no accepted models for the study of As-induced carcinogenesis. At the final meeting session we considered research needs. Among the most important areas cited were a) As metabolism and its interaction with cellular constituents; b) possible bioaccumulation of As; c) interactions with other metals; d) effects of As on genetic material; e) development of animal models and cell systems to study effects of As; and f) a better characterization of human exposures as related to health risks. Some of the barriers to the advancement of As research included an apparent lack of interest in the United States on As research; lack of relevant animal models; difficulty with adoption of uniform methodologies; lack of accepted biomarkers; and the need for a central storage repository for stored specimens.

Acute and chronic arsenic toxicity

“…Arsenic may cause a basal cell carcinoma in a non-melanin pigmented skin. 30 The latent period after exposure may be as long as 60 years and has been reported in patients treated with Fowler's solution, in sheep dip workers, in vineyard workers using arsenical pesticides, and from drinking contaminated wine. 63 Another manifestation due to arsenic deposition in keratinrich areas are prominent transverse white lines in the fingernails and toenails called Mee's lines.…”

“…Information is required to determine if there is a threshold for carcinogenic effects to manifest and also to define the dose and duration of exposure. 30 Studies are required to link toxic manifestations with possible genetic polymorphism, age, gender, nutritional status, and the protective role of vitamins, minerals, and antioxidants. There is a marked variation in clinical features among individuals in the same household as is commonly seen in Bangladesh.…”

Air Pollution and Public Health: A PRISMA-Compliant Systematic Review

“…Microorganisms are widespread in the atmosphere, soil and water, but different sources are well-known: mycetes are more concentrated in outdoor air [23], while bacteria emitted by human airways are more concentrated in indoor air [24]. Recently, urban wastes have been demonstrated to be a huge source of germ spores, and their storage and disposal could be hazardous for workers' health and public safety [25][26][27].…”

A Plant Model for Assessing Arsenic Phytotoxicity: Effect on Growth and Oxidative Stress Response Molecules

“…One set of the plants were kept without As treatment which served as the control. Plants were harvested at 0, 4,8,12,16,20,24,36, 48 and 72 h after As treatment.…”

“…Among the metal pollutants, Arsenic (As) is of major concern. As toxicity has been known for centuries which has received increased attention because of its chronic and epidemic effects on human [4]. As can be present in the terrestrial, marine as well as freshwater environments in various chemical forms.…”