A pilot-scale expanded target assessment of mixtures of inorganic and organic contaminants in point-of-consumption drinking water (tapwater, TW) was conducted in Puerto Rico (PR) to continue to inform TW exposures and corresponding estimations of cumulative human-health risks across the US. In August 2018, a spatial synoptic pilot assessment of than 524 organic, 37 inorganic, and select microbiological contaminant indicators was conducted in 14 locations (7 home; 7 commercial) across PR. A follow-up 3-day temporal assessment of TW variability was conducted in December 2018 at two of the synoptic locations (1 home, 1 commercial) and included daily pre- and post-flush samples. Concentrations of regulated and unregulated TW contaminants were used to calculate cumulative in vitro bioactivity ratios and Hazard Indices (HI) based on existing human-health benchmarks. Synoptic results confirmed that human exposures to inorganic and organic contaminant mixtures, which are rarely monitored together in drinking water at the point of consumption, occurred across PR and consisted of elevated concentrations of inorganic contaminants (e.g., lead, copper), disinfection byproducts (DBP), and to a lesser extent per/polyfluoroalkyl substances (PFAS) and phthalates. Exceedances of human-health benchmarks in every synoptic TW sample support further investigation of the potential cumulative risk to vulnerable populations in PR and emphasize the importance of continued broad characterization of drinking-water exposures at the tap with analytical capabilities that better represent the complexity of both inorganic and organic contaminant mixtures known to occur in ambient source waters. Such health-based monitoring data are essential to support public engagement in source water sustainability and treatment and to inform consumer point-of-use treatment decision making in PR and throughout the US.

在波多黎各 (PR) 对消费点饮用水（自来水，TW）中的无机和有机污染物混合物进行了试点扩大目标评估，以继续告知 TW 暴露情况和累积人类健康风险的相应估计遍布美国。2018 年 8 月，在波罗的海 14 个地点（7 个住宅；7 个商业）对超过 524 种有机污染物、37 种无机污染物和精选微生物污染物指标进行了空间天气试点评估。2018 年 12 月，在两个天气地点（1 个家庭、1 个商业地点）对 TW 变异性进行了后续 3 天时间评估，包括每日冲洗前和冲洗后样本。根据现有的人类健康基准，使用受管制和不受管制的 TW 污染物的浓度来计算累积体外生物活性比和危害指数 (HI)。概要结果证实，人类接触无机和有机污染物混合物（很少在饮用时在饮用水中一起监测）发生在整个 PR 范围内，其中包括浓度升高的无机污染物（例如铅、铜）、消毒副产物（DBP） ），以及较小程度的全氟烷基物质（PFAS）和邻苯二甲酸盐。每个天气性 TW 样本均超过人类健康基准，这支持进一步调查 PR 中弱势群体的潜在累积风险，并强调继续广泛描述水龙头处饮用水暴露特征的重要性，分析能力可以更好地代表两者的复杂性已知存在于环境水源水中的无机和有机污染物混合物。这种基于健康的监测数据对于支持公众参与水源可持续性和处理以及为波多黎各和整个美国的消费者使用点处理决策提供信息至关重要。