Co-occurrence of arseniasis and fluorosis due to indoor combustion of high fluorine and arsenic content coal in a rural township in northwest China: epidemiological and toxicological aspects

Abstract

A large number of fluorosis and arseniasis cases appeared in a mountainous area in northwest China. The residents relied on local inferior coal ("bone coal") of high fluorine and arsenic content for domestic heating and cooking. For deep-inside information about this rare case of co-endemia of fluorosis and arseniasis in the population in this special exposure scenario, a field investigation in one of the hyperendemic townships was conducted. The resident population registered (n = 27,713) was enrolled in the investigation. All cases were diagnosed and assigned to three symptom severity groups, that is severe, medium, and mild according to Chinese National Standard Criteria GB 16396-96 and to the technical guideline WS/T208-01 or WS/T211-01 issued by the Chinese Ministry of Health. Gender difference was analyzed by standardized incidence ratio. Age trend and severity trend were tested by χ(2) analysis. Fluorosis was diagnosed in 56.7% of the residents. Over 95% of the diagnosed arseniasis cases were simultaneously diagnosed with fluorosis symptoms. Combined fluorosis-arseniasis represented 11.9% of the total fluorosis cases and 6.7% of the local population. No gender-related differences in the prevalence of skeletal, dental, or dermal symptoms inside all severity groups were detected. Symptom severity increased with age. The high frequency of superposition of arseniasis with fluorosis might be due to the fact that the local resident population has been exposed to very high levels of fluorine and arsenic via the same exposure route.

Progressive Research in the Molecular Mechanisms of Chronic Fluorosis

“…Both arsenic and fluoride are ubiquitous in the environment. The co-exposure of fluorine and arsenic is mainly through drinking water [109][110][111] or burning coal [112,113]. The latter is a unique type in China, which was attributed to exposure to high levels of As and F in food and breathing As-laden air, caused by polluted food and air due to indoor combustion of coal [112,113].…”

“…The co-exposure of fluorine and arsenic is mainly through drinking water [109][110][111] or burning coal [112,113]. The latter is a unique type in China, which was attributed to exposure to high levels of As and F in food and breathing As-laden air, caused by polluted food and air due to indoor combustion of coal [112,113]. The interaction mechanism of these two elements is complicated, which may be independent, synergistic, or antagonistic [114].…”

Contemporary trends in toxicological research on arsenic

“… Co-exposure and possible interaction of As with other environmental toxicants is also a field of public concern. Most important appears to be co-exposure to fluoride, both by ground water pollution (Chouhan and Flora, 2010[ 18 ]) and by indoor combustion of coal (Lin et al, 2012[ 51 ]). Also, interactions with iron (Kumasaka et al, 2012[ 46 ]) and with nutritional deficiencies (Deb et al, 2012[ 23 ]) are a matter of present research.…”

Environmental Exposure and Hazards of Arsenic: A Review

“…For instance, Lin et.al addresses apoptotic mechanisms induced by coexposure with barium, which can additionally be present in Arsenic-containing drinking-water wells. Other publications report co-exposures of arsenic and fluoride 99 . Thus, Ma et.al describes a population-based study in a rural area in Northwest China with a large number of cases diseased with a blend of fluorosis and arseniasis.…”