Abstract

Background:

Reusing wastewater for irrigation is a longstanding practice that enhances crop yields and improves climate resilience. Without treatment, however, wastewater contains harmful pathogens and chemicals. Reuse of untreated wastewater has been shown to be harmful to the health of nearby communities, but the routes of exposure are unknown and do not appear to be occupational. Some routes occur throughout entire communities, such as food contamination. Other routes may be spatially dependent, such as spread by domestic animals or through aerosolization.

Objectives:

To examine whether those wastewater exposure routes with a spatial dependency affect health, we estimated the risks of diarrheal disease in children under age 5 associated with living near wastewater canals, while adjusting for potential individual- and household-level confounders.

Methods:

We conducted three surveys over 1 y in the Mezquital Valley, Mexico, to measure diarrhea in children. The distance between each participating household and a wastewater canal was measured using GPS coordinates. The association between proximity and diarrhea was estimated with a multilevel logistic regression model accounting for spatial autocorrelation.

Results:

A total of 564 households completed one to three surveys, resulting in 1,856 survey observations of 646 children. Children living $100\mathrm{m}$ from a canal had 45% lower odds of diarrhea than those living within $10\mathrm{m}$ of a canal, and children living $1000\mathrm{m}$ away had 70% lower odds of diarrhea [$100\mathrm{m}$ vs. $10\mathrm{m}$ adjusted odds ratio $\left(\text{OR}\right)=0.55$, 95% credible interval (CI): 0.33, 0.91; $1000\mathrm{m}$ vs. $10\mathrm{m}$ adjusted $\text{OR}=0.30$, 95% CI: 0.11, 0.82].

Discussion:

The estimated decline in diarrheal prevalence with household distance from a canal persisted after controlling for occupational exposure. Identifying the specific routes of exposure that drive this relationship will help identify which interventions, such as upstream treatment, can reduce health risks for entire communities where wastewater exposure occurs. https://doi.org/10.1289/EHP6443

中文翻译：

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在墨西哥梅斯基塔尔山谷中，模拟与未经处理的家庭污水直接灌溉相关的腹泻疾病的空间风险。

摘要

背景：

再利用废水进行灌溉是一项长期的实践，可以提高农作物的产量并提高气候适应能力。但是，未经处理，废水中会含有有害的病原体和化学物质。已经证明，未经处理的废水的再利用对附近社区的健康有害，但是接触途径未知，而且似乎不是职业。一些路线遍布整个社区，例如食物污染。其他路线可能是空间依赖的，例如由家畜传播或通过雾化传播。

目标：

为了检查那些具有空间依赖性的废水接触途径是否会影响健康，我们在调整潜在的个人和家庭层面混杂因素的同时，估计了5岁以下儿童与腹泻渠附近生活相关的腹泻病风险。

方法：

我们在墨西哥的梅斯基塔尔山谷（Mezquital Valley）进行了1年多的3次调查，以测量儿童的腹泻率。使用GPS坐标测量每个参与的家庭与废水渠之间的距离。接近性和腹泻之间的关联是通过考虑空间自相关的多级逻辑回归模型估算的。

结果：

共有564户家庭完成了1-3项调查，对646名儿童进行了1,856项调查。儿童生活$100\mathrm{米}$ 来自运河的人的腹泻几率比居住在运河中的人低45％ $10\mathrm{米}$ 运河，还有孩子们 $1000\mathrm{米}$ 发生腹泻的几率降低了70％[$100\mathrm{米}$ 与 $10\mathrm{米}$ 调整后的优势比 $（\text{要么}）=0.55$，95％可信区间（CI）：0.33、0.91； $1000\mathrm{米}$ 与 $10\mathrm{米}$ 已调整 $\text{要么}=0.30$，95％CI：0.11，0.82]。

讨论：

在控制了职业暴露之后，估计的腹泻患病率随着家庭到运河的距离而下降。确定驱动这种关系的具体接触途径将有助于确定哪些干预措施（例如上游处理）可以降低发生废水接触的整个社区的健康风险。https://doi.org/10.1289/EHP6443