Components of plastic: experimental studies in animals and relevance for human health

Abstract

Components used in plastics, such as phthalates, bisphenol A (BPA), polybrominated diphenyl ethers (PBDE) and tetrabromobisphenol A (TBBPA), are detected in humans. In addition to their utility in plastics, an inadvertent characteristic of these chemicals is the ability to alter the endocrine system. Phthalates function as anti-androgens while the main action attributed to BPA is oestrogen-like activity. PBDE and TBBPA have been shown to disrupt thyroid hormone homeostasis while PBDEs also exhibit anti-androgen action. Experimental investigations in animals indicate a wide variety of effects associated with exposure to these compounds, causing concern regarding potential risk to human health. For example, the spectrum of effects following perinatal exposure of male rats to phthalates has remarkable similarities to the testicular dysgenesis syndrome in humans. Concentrations of BPA in the foetal mouse within the range of unconjugated BPA levels observed in human foetal blood have produced effects in animal experiments. Finally, thyroid hormones are essential for normal neurological development and reproductive function. Human body burdens of these chemicals are detected with high prevalence, and concentrations in young children, a group particularly sensitive to exogenous insults, are typically higher, indicating the need to decrease exposure to these compounds.

Plastics, the environment and human health: current consensus and future trends

“…Some additive chemicals are potentially toxic (for example lead and tributyl tin in polyvinyl chloride, PVC), but there is considerable controversy about the extent to which additives released from plastic products (such as phthalates and bisphenol A, BPA) have adverse effects in animal or human populations. The central issue here is relating the types and quantities of additives present in plastics to uptake and accumulation by living organisms (Andrady & Neal 2009;Koch & Calafat 2009;Meeker et al 2009;Oehlmann et al 2009;Talsness et al 2009;Wagner & Oehlmann 2009). Additives of particular concern are phthalate plasticizers, BPA, brominated flame retardants and anti-microbial agents.…”

“…Research on experimental animals informs epidemiologists about the potential for adverse effects in humans and thus plays a critical role in chemical risk assessments. A key conclusion from the paper by Talsness et al (2009) is the need to modify our approach to chemical testing for risk assessment. As noted by these authors and others, there is a need to integrate concepts of endocrinology in the assumptions underlying chemical risk assessment.…”

“…As noted by these authors and others, there is a need to integrate concepts of endocrinology in the assumptions underlying chemical risk assessment. In particular, the assumptions that dose-response curves are monotonic and that there are threshold doses (safe levels) are not true for either endogenous hormones or for chemicals with hormonal activity (which includes many chemicals used in plastics) (Talsness et al 2009).…”

A novel, highly efficient method for the separation and quantification of plastic particles in sediments of aquatic environments

“…Those harmful consequences of plastic debris for aquatic organisms have been already shown (Gregory 2009). Next to mechanical impairments of swallowed plastics mistaken as food (e.g., Sheavly and Register 2007;Derraik 2002;Laist 1997), many plastic associated chemicals are proven to be carcinogenic, endocrine-disrupting, or acutely toxic (Lithner et al 2009;Oehlmann et al 2009;Talsness et al 2009). Additionally, plastic particles can adsorb and transport persistent organic "pollutants" such as polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE, Hirai et al 2011;Teuten et al 2009).…”

Polybrominated diphenyl ether, polychlorinated biphenyl, and dechlorane plus concentrations in human serum, and their relationships with thyroid hormones.

“…PBDE concentrations in human serum have increased exponentially in the last three decades [18,19]. PBDEs are structurally similar to thyroxine (T4), and it has been shown in in vivo animal studies that exposure to PBDEs can potentially lead to disruptions to thyroid homeostasis and TH functions [20][21][22][23][24]. It is also suspected that PBDEs can disrupt thyroid functions in humans, but reports of impacts of PBDE exposure on human thyroid functions have been controversial [25][26][27].…”