Suicide behaviour and arsenic levels in drinking water: a possible association?

Gianmarco Troiano, Isabella Mercurio, Paola Melai, Nicola Nante, Massimo Lancia, Mauro Bacci

A considerable part of the global population is exposed to arsenic-contaminated drinking water which is the main source of inorganic arsenic(As) exposure in humans. Arsenic exposure interferes with the action of enzymes, essential cations, and transcriptional events in cells throughout the body, and a multitude of multisystemic non-cancer effects might ensue. The aim of our review was to evaluate the effects of arsenic contamination in drinking water on suicides rates. A systematic literature search (English written literature) was conducted in electronic databases MEDLINE, SCOPUS. Evidences dating from 1999 till 2016 have been collected. A manual search of reference lists of included studies and review articles was successively performed. All references of the retrieved studies were also reviewed to avoid missing relevant publications. The key search terms included: "arsenic AND water AND suicide". The literature search yielded 13 publications, but we identified 2 manuscripts available for this systematic review. The 2 studies included in the review, were published in 2015 and in 2017 and settled in Italy and Hungary. The levels of arsenic in the waters ranged from 0.016 μg/l to >50 μg/l. The findings of the two studies are conflicting, in fact Pompili et al. reported an apparently beneficial effect of arsenic on suicides rates, with an inverse correlation of arsenic concentration and local suicide rates, in contrast to a positive correlation with natural-cause mortality rates. Our review led to conflicting results, so the diatribe about the real effects of arsenic intake of suicidal behaviors is still open. Therefore, we encourage other colleagues to conduct further studies in other locations in order to have more reliable results.