Department of Chemistry, University of Bath, Bath BA2 7AY, U.K.
Department of Psychology, University of Bath, Bath BA2 7AY, U.K.
Environ Sci Technol. 2021 Sep 7;55(17):11657-11666. doi: 10.1021/acs.est.1c01274. Epub 2021 Aug 23.
Down-the-drain disposal of pharmaceuticals remains an overlooked and unrecognized source of environmental contamination that requires nontechnological "at-source" solutions. Monitoring of 31 pharmaceuticals over 7 days in five wastewater treatment plants (WWTPs) serving five cities in South-West UK revealed down-the-drain codisposal of six pharmaceuticals to three WWTPs (carbamazepine and propranolol in city A, sildenafil in city B, and diltiazem, capecitabine, and sertraline in city D), with a one-off record codisposal of estimated 253 pills = 40 g of carbamazepine and estimated 96 pills = 4 g of propranolol in city A accounting for their 10- and 3-fold respective increases in wastewater daily loads. Direct disposal of pharmaceuticals was found to affect the efficiency of wastewater treatment with much higher pharmaceutical removal (decrease in daily load) during "down-the-drain disposal" days. This is due to lack of conjugated glucuronide metabolites that are cleaved during "consumption-only" days, with the release of a parent pharmaceutical counterbalancing its removal. Higher removal of pharmaceuticals during down-the-drain disposal days reduced pharmaceutical loads reaching receiving environment, albeit with significant levels remaining. The estimated daily loads in receiving water downstream from a discharge point accounted for 13.8 ± 3.4 and 2.1 ± 0.2 g day of carbamazepine and propranolol, respectively, during consumption-only days and peaked at 20.9 g day (carbamazepine) and 4.6 g day (propranolol) during down-the-drain disposal days. Actions are needed to reduce down-the-drain disposal of pharmaceuticals. Our recent work indicated that down-the-drain disposal of pharmaceuticals doubled since the last study in 2005, which may be due to the lack of information and messaging that informs people to dispose of unused medicines at pharmacies. Media campaigns that inform the public of how to safely dispose of medicines are key to improving rates of return and reducing pharmaceutical waste in the environment. The environment is a key motivator for returning unused medicines to a pharmacy and so messaging should highlight environmental risks associated with improper disposal.
将药品直接冲入下水道仍是一种被忽视且未被认识到的环境污染源，需要采取非技术的“源头”解决方案。对英国西南部五个城市的五家污水处理厂（WWTP）连续七天监测了 31 种药品，结果显示，有六家 WWTP 将六种药品与污水一起直接排入下水道（城市 A 中的卡马西平和普萘洛尔，城市 B 中的西地那非，以及城市 D 中的地尔硫卓、卡培他滨和舍曲林），城市 A 曾一次性记录到估计有 253 片 = 40 克卡马西平和 96 片 = 4 克普萘洛尔被直接冲入下水道，这导致其污水日负荷分别增加了 10 倍和 3 倍。研究发现，直接处理药品会影响污水处理效率，在“直接冲入下水道”期间，污水中药物的去除率（日负荷下降）更高。这是因为缺乏在“仅服用”期间被切断的共轭葡萄糖醛酸代谢物，而释放出的母体药物则抵消了其去除量。在直接冲入下水道期间，药品的去除率更高，进入受纳环境的药品负荷减少，尽管仍有大量残留。在排放点下游的受纳水中，仅在“仅服用”期间，估计日负荷分别为 13.8 ± 3.4 克和 2.1 ± 0.2 克卡马西平和普萘洛尔，而在直接冲入下水道期间，负荷最高可达 20.9 克/天（卡马西平）和 4.6 克/天（普萘洛尔）。需要采取行动减少药品直接冲入下水道。我们最近的研究表明，自 2005 年上一次研究以来，药品直接冲入下水道的情况增加了一倍，这可能是因为人们缺乏有关将未使用的药品送到药店处理的信息和宣传。向公众宣传如何安全处理药品的媒体宣传活动是提高返还率和减少环境中药物废物的关键。环境是促使人们将未使用的药品送回药店的关键因素，因此宣传信息应强调与不当处理相关的环境风险。
