A. What is a plasticizer Plasticizers (PAEs) are mainly used as plasticizers for plastics, but also as pesticide carriers, insect repellents and cosmetics and other raw materials. For example, artificial leather, plastic flooring, plastic tablecloths plastic raincoats, plastic slippers, shower curtains, plastic hoses and other household products, a variety of packaging plastic bags, cling film, plastic barrels and other materials, baby pacifiers, teething apparatus, soft toys, balloons and other children’s products and so on. Almost all plastic products contain large amounts of plasticizers. The composition of PAEs is complex. Some of these ingredients are toxic. The U.S. National Environmental Protection Agency has listed dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), di-n-octyl phthalate (DOP), and di(2-ethylhexyl) phthalate (DEHP) as priority toxic pollutants for control, and China has also identified DMP, DEP, and DOP DMP, DEP and DOP have been identified as environmental priority pollutants. PAEs into the body: 1, oral ingestion of PAEs through eating food containing PAEs or sucking PAEs-containing items into the body. However, so far, there is no report and assessment on the correlation between the concentration of PAEs in food and the concentration of PAEs in the body. The US CPSC concluded through simulation experiments that PAEs can enter the body through the route of sucking on PAEs-containing items, and this view was supported by the US CPSC and Bouma et al. 2. Transdermal absorption through the use of personal hygiene products and baby care products and exposure to PAEs may be an important route of exposure to PAEs for infants and children. Factors affecting the rate of dermal absorption of PAEs include the concentration of PAEs, the site of body contact, area, time, and the concentration of PAEs in the body. Children have a larger relative body surface area than adults, so children are more likely to absorb PAEs transdermally. 3. Intravenous entry into the body PAEs are able to enter the bloodstream directly through an intravenous infusion line. Because DEHP is bound in a plastic matrix with non-covalent bonds, it can easily precipitate out of the IV tubing into the bloodstream. The US FDA points out that newborns are at increased risk of exposure to PAEs through intravenous nutrition tubes, artificial heart-lung machines and blood vessels, and also points out that hospitalized newborns are at risk of exposure to high concentrations of PAEs and health effects¨. 4. PAEs in pregnant women can enter the fetus directly through the placental barrier via the placenta. However, no information is available on fetal exposure and metabolic kinetics during pregnancy. Intrauterine exposure of the developing fetus to PAEs may have extremely important implications for future health. PAEs have a short half-life, ranging from a few hours to a few days, and are rapidly excreted from the body. For example, DEHP that enters the body intravenously does not produce the same metabolites as oral ingestion, although the amount is the same as oral ingestion. The enzymes of the gastrointestinal tract are capable of converting DEHP to the water-soluble monoester MEHP that is readily absorbed intestinally. if DEHP enters the bloodstream directly via the vein, its metabolic conversion is slow and thus most of the parent compound is excreted directly from the urine. Therefore, the same dose of DEHP is more toxic to humans via intestinal absorption than via intravenous absorption. Both oral ingestion and transdermal absorption of PAEs produce large amounts of biologically active monoesters and oxidative metabolites. Therefore, both exposure dose and route of exposure need to be considered when assessing the health hazards of PAEs. (a) Effects on reproductive health 1. Men: Anti-androgenic activity leads to small penis development and shortening of the distance between the penis and the anus. It can inhibit sperm production and testosterone secretion in men and reduce sperm production in adulthood leading to infertility or reduced sexual performance or no sexual function. Vesiculation of vas deferens semen, prostate abnormalities, hypospadias, cryptorchidism, testicular injury, permanent papillary changes, and shortened distance between anus and genitals. Effects on reproduction: 1) PAEs affect the pulsatile release of gonadotropin-releasing hormone and gonadotropin from the hypothalamic-pituitary-testicular axis, causing sexual dysfunction. (2) PAEs damage spermatozoa in the testes through direct or indirect action.) DEHP may cause accelerated pentose phosphate bypass metabolism, leading to deficiency of reduced nicotinamide adenine dinucleotide phosphate, impaired testosterone synthesis and elevated acyl carrier protein activity in the testis, and altering certain enzyme activities in the rat testis. (4) DBP and DOP can penetrate the blood-testis barrier and act on germ cells, causing chromosomal aberrations such as chromosome loss or breakage, resulting in sperm deformities and interfering with the normal spermatogenesis process. 2, female: precocious sexual maturity, early breast development. Affects height and body shape. The shortening of pregnancy, especially DBP exposure, is also closely related to the occurrence of endometriosis in women. the effect of DBP on fertility can be caused by inhibiting luteinizing function and progesterone synthesis, so that the gestational progesterone is insufficient, and the pregnancy cannot be maintained. There are also mutagenic and carcinogenic effects, the mutagenic rate decreases with the increase of the length of alkyl chain. (ii) Immune system effects – allergic reactions In adults PAEs can induce asthma attacks, and children exposed to PAEs have a correlation with asthma and allergic reactions, and the mechanism is presumed to be that PAEs into the body can cause and participate in the immune response. (iii) Hepatotoxicity Experimental exposure of adult animals to high concentrations of PAEs can lead to tumors in the liver. The mechanism is that PAEs stimulate PPAR receptors and response elements by reducing apoptosis and activating growth regulator genes, altering the balance between cell growth and apoptosis, thus leading to tumorigenesis. However, human PPAR receptors do not induce downstream effects similar to those seen in animal studies, so the International Agency for Research on Cancer (IARC) changed DEHP from a “probable carcinogen” in 2000 to a “It is a non-carcinogen for human. Prevention: 1. Food: DBP and DEHP can be enriched and concentrated in the ecosystem through the food chain, especially in aquatic organisms, and can reach high concentrations. 2, reduce the reliance on plastic-type packaging, consciously reduce the use of plastic bags, redemption to buy hot cooked food to avoid the use of plastic products, if possible, edible oil with glass products or ceramic-type containers. 3, bottled water in high temperatures should be used with caution, especially if placed for a long time. 4, reduce the use of cosmetics, such as nail polish with the highest content, perfume (more than 90%), skin care and moisturizing products (45%), shampoo washing and hair care category (30%). 5, food, such as soaking instant noodles, should not use foam products to hold the soaking system. 6, pay attention to whether the instructions contain phthalates 7, the summer months of July, August and September more attention to the dangers of plasticizers on the human body.