School of Public Health, University of California, Berkeley, CA 94720-7367, USA.
Environ Res. 2013 Apr;122:81-7. doi: 10.1016/j.envres.2013.02.002. Epub 2013 Mar 1.
Whether long-term, low-level hydrogen sulfide (H2S) gas is a cause of health effects, including asthma, is uncertain. Rotorua city, New Zealand, has the largest population exposed, from geothermal sources, to relatively high ambient levels of H2S. In a cross-sectional study, the authors investigated associations with asthma in this population.
A total of 1637 adults, aged 18-65 years, were enrolled during 2008-2010. Residences and workplaces were geocoded. H2S exposures at homes and workplaces were estimated using city-wide networks of passive H2S samplers and kriging to create exposure surfaces. Exposure metrics were based on (1) time-weighted exposures at home and work; and (2) the maximum exposure (home or work). Exposure estimates were entered as quartiles into regression models, with covariate data.
Neither exposure metric showed evidence of increased asthma risk from H2S. However, some suggestion of exposure-related reduced risks for diagnosed asthma and asthma symptoms, particularly wheezing during the last 12 months, emerged. With the maximum exposure metric, the prevalence ratio for wheeze in the highest exposure quartile was 0.80 (0.65, 0.99) and, for current asthma treatment, 0.75 (0.52, 1.08). There was no evidence that this was caused by a "survivor effect".
The study provided no evidence that asthma risk increases with H2S exposure. Suggestions of a reduced risk in the higher exposure areas are consistent with recent evidence that H2S has signaling functions in the body, including induction of smooth muscle relaxation and reduction of inflammation. Study limitations, including possible confounding, preclude definitive conclusions.
长期低水平的硫化氢（H2S）气体是否会对健康产生影响，包括哮喘，目前还不确定。新西兰罗托鲁瓦市的居民从地热资源中接触到相对较高水平的环境 H2S，是世界上受 H2S 暴露影响最大的人群。在一项横断面研究中，作者研究了该人群中 H2S 暴露与哮喘之间的关系。
2008 年至 2010 年期间，共招募了 1637 名年龄在 18-65 岁之间的成年人。住所和工作场所都进行了地理编码。使用全市被动 H2S 采样器网络和克里金法来创建暴露面，估算家庭和工作场所的 H2S 暴露量。暴露量指标基于（1）家庭和工作场所的时间加权暴露量；以及（2）最大暴露量（家庭或工作）。将暴露量估计值作为四分位数输入回归模型，并结合协变量数据。
两种暴露指标均未显示 H2S 暴露与哮喘风险增加有关的证据。然而，一些结果表明，与 H2S 暴露相关的诊断性哮喘和哮喘症状风险降低，特别是在过去 12 个月内出现喘息。使用最大暴露量指标，最高暴露量四分位数组的喘息患病率比为 0.80（0.65，0.99），当前哮喘治疗的患病率比为 0.75（0.52，1.08）。没有证据表明这是幸存者效应造成的。
该研究没有提供证据表明哮喘风险会随着 H2S 暴露而增加。在较高暴露区域风险降低的提示与最近的证据一致，即 H2S 在体内具有信号传递功能，包括诱导平滑肌松弛和减少炎症。研究的局限性，包括可能的混杂因素，排除了明确的结论。
