[Subjective symptoms and miscarriage after drinking well water exposed to diphenylarsinic acid].

OBJECTIVE

An outbreak of neurological health disorder caused by drinking well water occurred in 2003 at one apartment building in Kamisu, Ibaraki, Japan. This was the first case of mass poisoning due to well water contaminated with diphenylarsinic acid (DPAA). Subsequently, other residents in Kamisu were confirmed to have drunk well water containing lower concentrations of DPAA. The present study aimed to investigate neurological and other subjective symptoms and miscarriage occurrences after DPAA exposure.

METHODS

Subjects were residents of Kamisu aged 10-65 years in 2004. Twenty residents (high-level exposure group) had lived in the apartment building and drunk well water containing DPAA at arsenic concentrations of 2,262 μg/L. The moderate/low-level exposure group (67 residents) had drunk other well water containing DPAA at arsenic concentrations of 2-230 μg/L (mean: 85 μg/L) and DPAA was detected in their hair or nails. A control group (134 residents), matched to the latter group by sex and age, had only drunk tap water. Public health nurses completed a questionnaire on symptoms, pregnancy, and miscarriage through interviews.

RESULTS

Dizziness, unsteadiness, dysesthesia, writing disturbance, diplopia, insomnia, melancholy, headache, itchiness, weight change, diarrhea, cough, and dyspnea were significantly higher in the moderate/low-level exposure group than in the control group. A similar tendency was found in the high-level exposure group. From 1999 through 2003, no miscarriages occurred among 15 pregnancies in the control group, while three miscarriages occurred among five pregnancies in the moderate/low-level group.

CONCLUSIONS

DPAA exposure via well water caused miscarriage, in addition to neurological and other subjective symptoms.