Health and environmental assessment of mercury exposure in a gold mining community in Western Mindanao, Philippines.
The small-scale gold mining activities using mercury began in the late 1980s in Sibutad, Western Mindanao. It is located very near the Murcielagos Bay with tailing ponds directly discharging into bodies of water. This cross-sectional study aimed to determine the health and environmental effects of gold mining activities on the community. Residents were randomly selected and classified into two groups, namely, the directly exposed and indirectly exposed populations using a set inclusion criteria. Complete medical and laboratory examinations were performed. Environmental and biologic samples were collected for total mercury and methylmercury determinations. The results showed that the directly exposed group had significantly higher mean blood total mercury and methylmercury levels in comparison with the indirectly exposed population. Although there were no significant differences between hair total mercury and methylmercury levels, there was a trend for higher levels of these biomarkers among the directly exposed residents as compared with the unexposed group. The absence of statistically significant differences may be attributable to the small sample size. Ambient air quality monitoring for mercury exceeded the allowable levels. However, levels of mercury in drinking water and sediments were within allowable limits. Frequency of gastrointestinal complaints was significantly associated with elevated hair methylmercury levels (p=0.02). Also, there appears to be a trend towards higher blood total mercury levels and frequency of gastrointestinal complaints (p=0.09). An interesting finding in this study was the increasing incidence of elevated diastolic blood pressure with elevated hair total mercury levels (p=0.07). Mercury storage at home is a risk factor.
Cortes-Maramba
Nelia
N
National Poison Control and Information Service, College of Medicine, University of the Philippines-Manila, Philippines.
Reyes
Jose Paciano
JP
Francisco-Rivera
Ana Trinidad
AT
Akagi
Hirokatsu
H
Sunio
Rose
R
Panganiban
Lynn Crisanta
LC
D000328:Adult; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005260:Female; D006046:Gold; D006262:Health; D006801:Humans; D008297:Male; D008628:Mercury / Q000008:administration & dosage / Q000009:adverse effects* / Q000032:analysis*; D008767:Methylmercury Compounds / Q000008:administration & dosage / Q000009:adverse effects / Q000032:analysis; D008875:Middle Aged; D008906:Mining; D016273:Occupational Exposure / Q000009:adverse effects / Q000706:statistics & numerical data*; D009792:Oceans and Seas; D010679:Philippines / Q000453:epidemiology
D008767:Methylmercury Compounds; D006046:Gold; D008628:Mercury