Table 1.

Sources and impacts on the endocrine system of common organic pollutants (POPs).

Pollutant	Source of Pollutant	Impact on Endocrine System
Polychlorinated biphenyls (PCBs)	Industrial chemicals (mainly electrical products) [19,34]	Disrupts thyroid homeostasis Estrogen and androgen agonistic and antagonistic properties [19,35]
Dichlorodiphenyltrichloroethane (DDT)	Pesticide Currently used to rid vectors of disease in parts of the world [30]	Antiandrogenic properties Hypothesized xenoestrogen properties Hypothesized to work in additive way with other EDC pollutants [36,37]
Polycyclic aromatic hydrocarbons (PAHs)	Synthetic chemical used in industries, food preparation and cigarettes [19,38]	Agonist and antagonist of estrogen [19,38]
Bisphenol A (BPA)	Industrial chemical used for plastic and resin [19,38]	Xenoestrogen: binds and activates estrogen receptor Antiandrogen: binds and blocks androgen receptor Modifies steroid synthesis and affects its circulating concentration Affects peroxisome proliferator-activated receptors (PPARs), altering regulation of gene expression Disturbs thyroid and glucocorticoid signaling [19,39]
Phthalates	Industrial chemical used in plastics [19,38]	Strong antiandrogenic properties (weak estrogenic properties) [40]
Polybrominated diphenyl ethers (PBDEs)	Class of fire-retardant chemicals [41]	Disruption of thyroid hormone regulation by binding to thyroid nuclear and transporter receptors Agonist and antagonist of estrogen, androgen and progesterone receptors [19,41,42]