内蒙古改水干预12年后地方性砷中毒患者皮肤改变情况分析

Skin changes in patients with endemic arsenism after changing drinking water for 12 years in Inner Mongolia

目的了解内蒙古饮水型砷中毒病区人群在改水干预12年后皮肤损伤的变化情况，评估饮水型砷中毒对人体产生的远期危害、迟发型伤害以及改水干预所产生的效果。方法以改水前（2004年）砷暴露地区整群分层抽样调查对象（资料来源于内蒙古自治区综合疾病预防控制中心）作为基础，2017年选取内蒙古巴彦淖尔市（五原县的胜丰乡和杭锦后旗的沙海乡）3个行政村（2005年改水）作为调查点，以符合条件的既往调查对象且一直在调查点生活的居民作为本次的研究对象（n = 80，男性35人、女性45人）。对比改水前后砷暴露居民的皮肤损害情况，采集调查对象饮用水水样进行砷含量测定。按水砷暴露水平将调查对象分为低、中、高暴露组（10 ~、150 ~、≥300 μg/L），分析改水前后皮肤损害临床分度改变情况。结果改水后调查对象饮用水砷含量[中位数（范围）]为1.42（0.18 ~ 33.45）μg/L，改水前为238.20（14.56 ~ 824.70）μg/L，二者比较差异有统计学意义（Z = - 8.34，P 〈 0.05）。改水后共查出皮肤角化者63人、色素沉着者7人、色素脱失者19人，而改水前分别为38、3、18人。改水后皮肤角化检出率明显高于改水前[78.8%（63/80）比47.5%（38/80），χ2 = 16.78，P 〈 0.05]。从皮肤损害临床分度来看，改水后砷暴露人群皮肤损害临床分度检出正常者23人，可疑44人、轻度10人、中重度3人，而改水前分别为38、18、6、18人。改水后与改水前相比，砷暴露人群中皮肤损害临床分度可疑检出率明显上升，中重度检出率明显下降（χ2 = 17.80、12.33，P均〈 0.05）；男性皮肤损害临床分度中重度皮肤损害检出率明显下降（χ2 = 7.65，P 〈 0.05）；女性皮肤损害临床分度正常检出率降低、可疑检出率升高（χ2 = 5.48、7.65，P均〈 0.05）。高、中暴露组分别有41.9%（13/31）及42.9%（12/28）的砷暴露人群皮肤损害临床分度减轻，而皮肤损害临床分度加重情况在高、中、低暴露组的比率分别为25.8%（8/31）、25.0%（7/28）、42.9%（9/21），线性趋势χ2检验结果显示，差异有统计学意义（χ2 = 12.96，P 〈 0.05）。结论改水可以有效改善砷致皮肤损伤程度，但长期慢性砷暴露引起的皮肤损伤也会持续发生，砷致机体的远期效应仍需继续探索。

ObjectiveTo understand the changes of skin lesions in population exposed to arsenic through drinking-water in Inner Mongolia after changing water source for 12 years, and to evaluate the long-term harmful effects and the delayed injury to human body due to arsenic exposure and the effect of changing water.MethodsThe stratified random cluster sampling investigation objects （data derived from the Inner Mongolia Autonomous Region Comprehensive Center for Disease Control and Prevention） of the arsenic exposure area before water reform （2004） as the foundation, in 2017, we selected three administrative villages （changed water in 2005） in Bayan Nur City of Inner Mongolia as survey sites. The objects of this study were residents who had been living in the survey site and were eligible for previous survey （n = 80, 35 males and 45 females）. To compare the skin damage of the residents exposed to arsenic before and after the water changed, the water samples of the survey objects were measured arsenic content. According to the content of water arsenic, the respondents were divided into low, medium and high exposure groups （10 -, 150-, ≥300 μg/L）, to analyze clinical classification in skin damage before and after changing water.ResultsThe water arsenic content after changing [1.42 （0.18 - 33.45） μg/L] was lower than those before the changes [238.20 （14.56 - 824.70） μg/L, Z = - 8.34, P 〈 0.05]. A total of 63 persons with skin keratinization, 7 persons with hyperpigmentation and 19 persons with depigmentation were identified after the changes of drinking water source, while 38, 3 and 18 persons were respectively found before the changes. The detection rate of skin keratinization after water changes was significantly higher than that before water changes [78.8% （63/80） vs 47.5% （38/80）, χ2 = 16.78, P 〈 0.05]. According to the clinical classification of skin damage, 23 patients were normal, 44 patients were suspicious, 10 patients were mild, and 3 patients were moderate or severe after the water changes, compared with those before the water changes （38, 18, 6 and 18 persons were respectively found）, the clinical fractional suspicious detection rate of skin damage in the arsenic exposed population increased, and the medium-severe detection rate decreased, and the differences were statistically significant （χ2 = 17.80, 12.33, P 〈 0.05）. The detection rate of the clinical score of moderate-severe skin damage in men was significantly decreased, and the difference was statistically significant （χ2 = 7.65, P 〈 0.05）. The normal detection rate of female skin lesions was reduced, and the rate of suspected detection was increased （χ2 = 5.48, 7.65, P 〈 0.05）. In the high- and medium-dose groups, 41.9% （13/31） and 42.9% （12/28） of the arsenic exposure population had a reduced clinical classification of skin damage. The ratios of clinical classification severity of skin damage in the high-, medium- and low-dose groups were 25.8% （8/31）, 25.0% （7/28）, and 42.9% （9/21）. The differences were statistical significantly by linear trend chi-square test （χ2 = 12.96, P 〈 0.05）.ConclusionsThe skin lesions exposed to arsenic could be effectively improved after changing water. But the skin lesions still appear in some cases due to long-term chronic arsenic exposure. The long-term effects caused by arsenic should be explored persistently.