Many of the products and drugs used commonly contain chemical components which may persist through sewage treatment works (STW) and eventually enter the aquatic environment as parent compounds, metabolites, or transformation products. Pharmaceuticals and personal care products (PPCPs) and other emerging contaminants (ECs) have been detected in waters (typically ng/L) as well as more recently bound to sediment and plastic particles (typically ng/g). Despite significant advancement of knowledge since the late 1990s, the fate of these contaminants/transformation products once introduced into the aquatic environment remains relatively unresolved. This review provides a unique focus on the fate of seven major groups of PPCPs/ECs in the aquatic environment, which is frequently not found in similar works which are often compound or topic-specific and limited in background knowledge. Key findings include: a) some replacements for regulation precluded/banned chemicals may be similarly persistent in the environment as those they replace, b) the adsorption of potentially bioactive chemicals to micro- and nanoplastics is a significant topic with risks to aquatic organisms potentially greater than previously thought, and c) micro-/nanoplastics are likely to remain of significant concern for centuries after regulatory limitations on their use become active due to the slow degradation of macro-plastics into smaller components. An interdisciplinary perspective on recent advances in the field is presented here in a unique way which highlights both the principle science and direction of research needed to elucidate the fate and transport patterns of aquatic PPCPs/ECs. Unlike similar reviews, which are often topic-specific, here we aim to present an overarching review of the field with focus on the occurrence, transformation and fate of emerging contaminants. Environmental presence of seven major classes of contaminants (analygesics, antibiotics, antineoplastics, beta-blockers, perfluorinated compounds, personal care products and plasticisers), factors affecting contaminant fate, association with plastic micro-/nanoparticles and photochemical transformation are comprehensively evaluated.

Pharmaceuticals and personal care products (PPCPs), other emerging contaminants (ECs), and metabolites thereof are ubiquitous in the environment, both built and natural. While such compounds have been environmentally present for some time, new pharmaceuticals and replacements for other ECs phased out due to regulatory limitations are continually being introduced to market. Non-target lower organisms are exposed through affected water, atmospheric emissions, precipitation, sediments, among other routes. Biological disruption/dysfunction (such as endocrine, developmental, and epigenetic disruption) has been reported in lower organisms exposed to trace levels of PPCPs and other ECs. Such disruption/dysfunction may not be exclusively present as traditional toxic response (e.g., cancer or death) but may only slightly alter natural biological processes as a result of exposure to an exogenous chemical (e.g., an increased heart rate or altered size of dorsal fat pads in fish). The epigenome and endocrine system appear to be relatively sensitive to many PPCPs/ECs, particularly during early development. Humans are exposed to ECs such as plasticizers and perfluorinated compounds (PFCs) mainly through ingestion (food and contaminated liquid) as well as interaction with day-to-day products (detergents, musk compounds in fragrances, etc.). Few, if any, studies have investigated trace-level toxicity of such ECs to humans as direct-exposure trials are highly unethical. However, numerous epidemiological links exist between the presence of contaminants in humans (blood, urine, and tissues) and the occurrence of diseases or other phenotypic alterations. Despite mounting interest and research, such trace-level effects on humans are greatly debated and often criticized. This paper reviews the current understanding of PPCP/EC toxicity. Discussion of general biological disruption/dysfunction of the following seven classes of PPCP/ECs is included: analgesics, antibiotics, antineoplastic compounds, beta-blockers, endocrine disrupting compounds, PFCs, and plasticizers. A review of receptor-mediated toxicity, non-monotonic dose response relationships, developmental toxicity, and environmental epigenetics is also included. Lastly, an overview of the proposed toxicity to humans is provided including discussion of significant criticism and direction of future research.