Pharmaceuticals in soils of lower income countries: Physico-chemical fate and risks from wastewater irrigation

Abstract

Population growth, increasing affluence, and greater access to medicines have led to an increase in active pharmaceutical ingredients (APIs) entering sewerage networks. In areas with high wastewater reuse, residual quantities of APIs may enter soils via irrigation with treated, partially treated, or untreated wastewater and sludge. Wastewater used for irrigation is currently not included in chemical environmental risk assessments and requires further consideration in areas with high water reuse. This study critically assesses the contemporary understanding of the occurrence and fate of APIs in soils of low and lower-middle income countries (LLMIC) in order to contribute to the development of risk assessments for APIs in LLMIC. The physico-chemical properties of APIs and soils vary greatly globally, impacting on API fate, bioaccumulation and toxicity. The impact of pH, clay and organic matter on the fate of organic ionisable compounds is discussed in detail. This study highlights the occurrence and the partitioning and degradation coefficients for APIs in soil:porewater systems, API usage data in LLMICS and removal rates (where used) within sewage treatment plants as key areas where data are required in order to inform robust environmental risk assessment methodologies.

Application of prioritization approaches to optimize environmental monitoring and testing of pharmaceuticals

“…Only three prioritizations included or focused on the sediment compartment (Al-Khazrajy and Olsen et al 2013;Casado-Martinez et al 2017). Another exposure pathway overlooked in the vast majority of reviewed approaches is the application of biosolids (Guo et al 2016) and reclaimed irrigation waters (Lees et al 2016) to agricultural fields. Agricultural soil exposure is derived from sludge concentrations of pharmaceuticals in WWTPs, which is the result of sorption characterized by the sludge/water partition coefficient (Kd) (Berthod et al 2017 The absence of ecotoxicity data or validated ecotoxicity models available, is another factor which may have contributed to the scope of reviewed prioritizations encapsulating only the water column.…”

“…The use of both treated and untreated reclaimed wastewater and biosolids in agriculture is a widely adopted practice in countries suffering from water shortages such as Mexico, Israel, Australia and Southern Europe. (Asano et al 2007;Pedrero et al 2010;Dalkmann et al 2012;Lees et al 2016) Further, crops are grown on agricultural soils and cattle producing meat and milk are grazing on grasslands that have been amended with sludge-based biosolids and/or reclaimed wastewater, which poses a potential risk of indirect human exposure via these products (Mohapatra et al 2016;Paz et al 2016;Kinney et al 2006a), which was previously demonstrated (Mottaleb et al 2016;Franklin et al 2016;Malchi et al 2014).…”

Thermal baths as sources of pharmaceutical and illicit drug contamination

“…In addition to communal sewage (Kasprzyk-Hordern et al 2008;König et al 2017;Roberts and Thomas 2006), PhACs can contaminate the environment via other legal sources, such as grey waters used for irrigation (Etchepare and van der Hoek 2015;Lees et al 2016). Thermal spa water that has been discharged into natural waters is also considered to be a legal source of contamination.…”

Heterogeneous and homogeneous photocatalytic degradation of psychoactive drug Fluvoxamine: kinetic study, inorganic ions and phytotoxicity evaluation

“…Pharmaceutically active compounds (PhACs), emerging extensively in ecosystems as pollutants, have become an important environmental and public health issue, since they can contaminate drinking water and pose threats to wildlife and human health . Many studies, following their occurrence and fate, have reported their presence in water, soil, sediment, sludge as well as in drinking water . This is of major concern because PhACs are extensively and increasingly used in human and veterinary medicine, resulting in their continuous release in the environment .…”

“…1,2 Many studies, following their occurrence and fate, have reported their presence in water, soil, sediment, sludge as well as in drinking water. 3,4 This is of major concern because PhACs are extensively and increasingly used in human and veterinary medicine, resulting in their continuous release in the environment. 5 They are mostly introduced in the sewage system through excretion of unmetabolized compounds after medical use or inappropriate disposal 6 and insufficient removal by conventional wastewater treatment plants (WWTPs), 7 which are not designed to treat water polluted with pharmaceuticals present at trace levels.…”