Arseniasis prevalence and mortality in a multiethnic, endemic township in Guizhou, China.
OBJECTIVE
Farmers in Southwest Guizhou Autonomous Prefecture, China, represent a unique case of arseniasis, which is related to indoor combustion of high arsenic-containing coal instead of to arsenic-contaminated drinking water. A significant difference in the prevalence of arseniasis was observed in two neighboring ethnic clans in one village. The question arose whether the ethnicity-dependent difference observed in this village was more widely spread throughout the whole township. An epidemiologic investigation was designed to explore arseniasis distribution and mortality among all four ethnic groups in a multiethnic township.


METHODS
The cohort of arseniasis patients, diagnosed and registered in the overall field survey of 1991 as well as all the asymptomatic residents of the township, were enrolled in the present investigation. Indirect standardization was used for calculating the age-adjusted standardized incidence ratio (SIR) of arseniasis, the standardized mortality ratio (SMR) of various death causes (including some cancers), and their corresponding intervals of 95% confidence in both genders and in each local ethnic group.


RESULTS
The descending rank of arseniasis SIRs among local ethnic groups was found as: Hui>Han>Bouyei>Hmong. The descending rank of SMRs of malignancies was displayed as: Han>Hui>Bouyei>Hmong in males and both genders together as well. Concerning deaths of non-malignant causes the rank was observed as: Hui>Han>Bouyei>Hmong in males. The arseniasis SIR for ethnic Hmong residents (both genders combined) was found to be significantly less profound than the overall level in the township. No death cases in diagnosed ethnic Hmong patients and no cases of death from malignant causes in asymptomatic Hmong residents were recorded. The significant increase of arseniasis prevalence was observed in all males, compared with the overall prevalence of all residents. However, a significantly lower prevalence was seen in all females.


CONCLUSIONS
Significant ethnicity-dependent difference in arseniasis prevalence and mortality from all causes was found in a multiethnic rural township where farmers have been exposed to the indoor combustion of high arsenic coal for decades. The ethnic Hmong residents seemed to be the least susceptible to arseniasis among the four local ethnic groups.
Chen
Ji-gang
JG
Shanghai Institutes for Biological Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
Lin
Guo-fang
GF
Chen
Yu-gang
YG
Jia
Chao-gang
CG
Zhou
Yun-shu
YS
Meng
Hong
H
Guo
Wei-chao
WC
Golka
Klaus
K
Liu
Ke Jian
KJ
Shen
Jian-hua
JH
D000383:Agriculture; D016902:Air Pollution, Indoor / Q000009:adverse effects* / Q000032:analysis; D020261:Arsenic Poisoning / Q000208:ethnology* / Q000401:mortality; D002681:China / Q000453:epidemiology; D003031:Coal / Q000009:adverse effects*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007642:Keratosis / Q000139:chemically induced / Q000208:ethnology; D008297:Male; D009026:Mortality / Q000208:ethnology*; D009369:Neoplasms / Q000208:ethnology / Q000401:mortality; D017678:Sex Distribution
D003031:Coal