Oregon State University, College of Public Health and Human Sciences, Corvallis, OR, 97331, USA.
Benedict College, Department of Computer Science, Physics, and Engineering, Columbia, SC, 29204, USA.
J Expo Sci Environ Epidemiol. 2023 Jan;33(1):102-110. doi: 10.1038/s41370-022-00498-7. Epub 2022 Nov 14.
Sanitary sewage overflows (SSOs) release raw sewage, which may contaminate the drinking water supply. Boil water advisories (BWAs) are issued during low or negative pressure events, alerting customers to potential contamination in the drinking water distribution system.
We evaluated the associations between SSOs and BWAs and diagnoses of gastrointestinal (GI) illness in Columbia, South Carolina, and neighboring communities, 2013-2017.
A symmetric bi-directional case-crossover study design was used to assess the role of SSOs and BWAs on Emergency Room and Urgent Care visits with a primary diagnosis of GI illness. Cases were considered exposed if an SSO or BWA occurred 0-4 days, 5-9 days, or 10-14 days prior to the diagnosis, within the same residential zip code. Effect modification was explored via stratification on participant-level factors (e.g., sex, race, age) and season (January-March versus April-December).
There were 830 SSOs, 423 BWAs, and 25,969 cases of GI illness. Highest numbers of SSOs, BWAs and GI cases were observed in a zip code where >80% of residents identified as Black or African-American. SSOs were associated with a 13% increase in the odds of a diagnosis for GI illness during the 0-4 day hazard period, compared to control periods (Odds Ratio: 1.13, 95% Confidence Interval: 1.09, 1.18), while no associations were observed during the other hazard periods. BWAs were not associated with increased or decreased odds of GI illness during all three hazard periods. However, in stratified analyses BWAs issued between January-March were associated with higher odds of GI illness, compared to advisories issued between April-December, in all three hazard periods.
SSOs (all months) and BWAs (January-March) were associated with increased odds of a diagnosis of GI illness. Future research should examine sewage contamination of the drinking water distribution system, and mechanisms of sewage intrusion from SSOs.
Sewage contains pathogens, which cause gastrointestinal (GI) illness. In Columbia, South Carolina, USA, between 2013-2017, there were 830 sanitary sewage overflows (SSOs). There were also 423 boil water advisories, which were issued during negative pressure events. Using case-crossover design, SSOs (all months) and boil water advisories (January-March) were associated with increased odds of Emergency Room and Urgent Care diagnoses of GI illness, potentially due to contamination of the drinking water distribution system. Lastly, we identified a community where >80% of residents identified as Black or African-American, which experienced a disproportionate burden of sewage exposure, compared to the rest of Columbia.
卫生污水溢漏（SSO）会释放未经处理的污水，从而可能污染饮用水供应。在出现低气压或负气压事件时，会发布沸水警告（BWA），提醒客户注意饮用水分配系统中存在的潜在污染。
我们评估了南卡罗来纳州哥伦比亚市及其周边社区 2013-2017 年期间 SSO 与 BWA 与胃肠道（GI）疾病诊断之间的关联。
采用对称双向病例交叉研究设计，评估 SSO 和 BWA 对急诊和紧急护理就诊中 GI 疾病的主要诊断的影响。如果 SSO 或 BWA 在诊断前 0-4 天、5-9 天或 10-14 天内发生在同一邮政编码内，则将病例视为暴露。通过分层探讨参与者水平因素（如性别、种族、年龄）和季节（1 月至 3 月与 4 月至 12 月）的效应修饰作用。
共发生了 830 次 SSO、423 次 BWA 和 25969 例 GI 疾病。在一个邮政编码中，超过 80%的居民被认定为黑人或非裔美国人，该邮政编码中 SSO、BWA 和 GI 病例数量最多。与对照期相比，SSO 在 0-4 天的危险期内，胃肠道疾病诊断的几率增加了 13%，而其他危险期则没有关联（比值比：1.13，95%置信区间：1.09，1.18）。BWA 与所有三个危险期内 GI 疾病诊断的几率增加或减少均无关。然而，在分层分析中，与 4 月至 12 月发布的 BWA 相比，1 月至 3 月发布的 BWA 与所有三个危险期内 GI 疾病诊断的几率增加有关。
SSO（所有月份）和 BWA（1 月至 3 月）与 GI 疾病诊断几率的增加有关。未来的研究应该检查饮用水分配系统中的污水污染情况，以及 SSO 引起的污水入侵机制。
污水中含有导致胃肠道（GI）疾病的病原体。在美国南卡罗来纳州哥伦比亚市，2013-2017 年间，发生了 830 次卫生污水溢漏（SSO）。还发布了 423 次沸水警告（BWA），这是在出现负气压事件时发布的。使用病例交叉设计，SSO（所有月份）和沸水警告（1 月至 3 月）与急诊和紧急护理胃肠道疾病诊断几率的增加有关，这可能是由于饮用水分配系统受到污染。最后，我们发现一个社区中，超过 80%的居民被认定为黑人或非裔美国人，与哥伦比亚市的其他地区相比，他们受到污水暴露的影响不成比例。
