The history of arsenical pesticides and health risks related to the use of Agent Blue

Abstract

Arsenicals in agriculture. Beginning in the 1970s, the use of arsenic compounds for such purposes as wood preservatives, began to grow. By 1980, in the USA, 70% of arsenic had been consumed for the production of wood preservatives. This practice was later stopped, due to the US Environmental Protection Agency (EPA) ban of the arsenic-and chromium-based wood preservative chromated copper arsenate. In the past, arsenical herbicides containing cacodylic acid as an active ingredient have been used extensively in the USA, from golf courses to cotton fields, and drying-out the plants before harvesting. The original commercial form of Agent Blue was among 10 toxic insecticides, fungicides and herbicides partially deregulated by the US EPA in February 2004, and specific limits on toxic residues in meat, milk, poultry and eggs, were removed. Today, however, they are no longer used as weed-killers, with one exception - monosodium methanearsonate (MSMA), a broadleaf weed herbicide for use on cotton. Severe poisonings from cacodylic acid caused headache, dizziness, vomiting, profuse and watery diarrhea, followed by dehydration, gradual fall in blood pressure, stupor, convulsions, general paralysis and possible risk of death within 3-14 days.The relatively frequent use of arsenic and its compounds in both industry and agriculture points to a wide spectrum of opportunities for human exposure. This exposure can be via inhalation of airborne arsenic, contaminated drinking water, beverages, or from food and drugs. Today, acute organic arsenical poisonings are mostly accidental. Considerable concern has developed surrounding its delayed effects, for its genotoxic and carcinogenic potential, which has been demonstrated in epidemiological studies and subsequent animal experiments. <b>Conclusions.</b> There is substantial epidemiological evidence for an excessive risk, mostly for skin and lung cancer, among humans exposed to organic arsenicals in occupational and environmental settings. Furthermore, the genotoxic and carcinogenic effects have only been observed at relatively high exposure rates. Current epidemiological and experimental studies are attempting to elucidate the mechanism of this action, pointing to the question whether arsenic is actually a true genotoxic, or rather an epigenetic carcinogen. Due to the complexity of its effects, both options remain plausible. Its interactions with other toxic substances still represent another important field of interest.

Levels of heavy metals in soil and vegetables and associated health risks in Mojo area, Ethiopia

“…However, a relatively much higher concentration of (51.52 mg/kg) arsenic level in surface soil from West Bengal, India have been reported [68]. Arsenic (As) has long been regarded as environmental contaminant though its use is still continued [69,70] and can be released to the environment via both natural (biogeochemical) and anthropogenic activities [71]. This can be witnessed by the high concentration of arsenic found in the soil samples we have analyzed in this study.…”

Radionuclides and heavy metals in soil, vegetables and medicinal plants in suburban areas of the cities of Belgrade and Pancevo, Serbia

“…Ar senic was de tected in veg e ta bles col lected from Sur~in in 2013-2014, with the av er age con centra tion be ing 0.58 mgkg -1 (0.25-0.84 mgkg -1 ), tab. 3, point ing to the ef fects of in ten sive ag ri cul tural pro duction, i. e. the use of her bi cides and in sec ti cides [24], as well as the use of phos phate fer til iz ers con tain ing As [25]. How ever, re search con ducted in 2016-2017 showed that ar senic was not pres ent in the veg e ta bles at this lo ca tion.…”

Risk factors for primary lung cancer among never-smoking women in South Korea: a retrospective nationwide population-based cohort study

“…However, additional analyses stratified by age implied that the relative risk between urban and rural residence was not a differential misclassification bias. Individuals residing in rural locations may have greater exposure to potential carcinogens such as arsenics in pesticides [27], asbestos, and herbicides [28], which increase the risk of lung-cancer development.…”