Pharmaceuticals and Personal Care Products as Contaminants of Emerging Concern in Sewage Sludge and Soils and the Role of Transformation Products in Their Fate and Environmental Impact

Abstract

Human pharmaceuticals and personal care products (PPCPs) are a class of chemicals that range from medications to cleaning agents, showing diverse chemical properties. These chemicals have been placed in a variety of products, some of which are available over the counter and are commonly used. Since many PPPCPs enter the environment they have been commonly identified as contaminants of emerging concern (CECs). Many PPCPs are released form households where they enter the municipal waste stream and ultimately enter a wastewater treatment facility (WWTF). Researchers have characterized the presence of PPCPs through the waste stream and treatment facilities and ultimately in aquatic and terrestrial environments impacted by wastewater treatment end products. In comparison with parent PPCPs, transformation products (TPs) of these compounds are poorly characterized in the same environments. However, mounting evidence suggests that understanding TPs is as critical to understanding the fate and effects of PPCPs as the parent compound. Human metabolites of many PPCPs are known, but TPs of PPCPs can be produced in WWTFs and after be released in the natural environment. PPCPs that are in WWTFs are commonly transformed by both biotic and abiotic processes and not removed from the water system but released along with the TPs into surface waters, that may be used for municipal drinking water downstream or increasingly used as a source of non-potable water for agricultural uses. Some PPCPs and TPs can partition into the sludge phase during wastewater treatment, with a large portion of sludge produced being land-applied as a soil amendment (biosolids). The effects on the environment at times are difficult to quantify because the repercussions can be far reaching and there is a great need to elucidate the pathways and TPs formed as well as the effects on the biome.