Effects of Chemical Substances in the Environment on Female Reproductive Function

2 Mechanism of action Many factors such as age, ovarian reserve, sexually transmitted diseases, genetic hormone imbalance, male fertility and environment can affect women's reproductive function. Environmental factors include endocrine disruptors, heavy metal organic solvents, pesticides, and other chemical substances. More and more exposure to the above-mentioned chemicals in work and daily life It is estimated that at least 51 kinds of chemical substances that have toxic effects on reproductive functions are commonly found in living environments, and may be involved in embryonic development, puberty, reproductive age, and menopause. Injury to the female pituitary gland, ovary, uterus, mammary gland and neuroendocrine system, leading to female reproductive dysfunction 1 The biological basis of toxic substances in the environment on the damage to reproductive function The time and frequency of exposure to toxic substances in the environment Important factors affecting the function of the immune endocrine system; and the sensitivity of target tissues to toxic substances in the environment, both in relation to the various stages of female development (embryonic adolescence, reproductive period), but also with the cumulative contact time and quantity, will be Chemicals that interfere with normal endocrine function This is called an endocrine disruptor, and chemicals that damage the immune system are called immunotoxins. The former can act as hormone receptor agonists or antagonists, mimic or block the response of target cells to the corresponding hormones, leading to abnormal embryonic development during pregnancy. Immunotoxins can inhibit the secretion of macrophages and T cell cytokines, blocking The latter mediates the transmission of information between immune cells. Impairment of immune function can have extremely detrimental effects on the reproductive system. Damage to the two systems described above can lead to abnormalities in the hypothalamic-adenohypophysial-glandular axis and reduce fertility. For example, newborns consume dioxin milk. , can cause lymphoid tissue atrophy and growth stagnation; pregnant women drinking can lead to an increase in the rate of stillbirths Endocrine disruptors in the environment can directly damage the female reproductive function, and the role of immunotoxins is indirect if the former chemical structure and endogenous hormones, growth Similar factors, can directly enter the reproductive organs, affect cell differentiation, mitotic apoptotic migration of intracellular signal transduction, DNA repair and mitochondrial function, resulting in abnormal tissue proliferation, function changes or even necrosis, for example, cell proliferation depends mainly on mitochondria supply of energy, When chemical poisons in the environment interfere with mitochondrial function, cells will stop growing due to lack of energy. In severe cases, even when they die, mismatch repair of DNA during replication is indispensable for tissue proliferation and differentiation. This function can be damaged. Causes abnormal cell growth and tumorigenesis. Sometimes environmental toxicants must be converted in vivo to produce toxic effects. For example, some phytoestrogens have biological effects in the gastrointestinal tract and liver. As previously mentioned, the balance of hormones in the body is the human development, sexual function, and egg. Generate indispensable important conditions. Chemicals in certain environments can mimic or block the action of endogenous hormones and alter the function of the above-mentioned reproductive system. Some chemicals are lipid-soluble as steroid hormones. They diffuse through the cell membrane, and interact with the cytoplasm. The hormone hormone receptor binds to and enters the nucleus and activates or inhibits gene expression to produce biological effects. For example, although the chemical structure of DDT and ethenestrol is different from that of estrogen, it can bind to the estrogen receptor in the cytoplasm, leading to Female genital function impairment and tumorigenesis need to point out that the toxicity of environmental toxic chemicals and estrogen receptors is 100,000 times lower than that of endogenous estrogens, so some people think that eating phytoestrogen will not harm the health of the body but it is worth noting that Some chemical poisons are fat-soluble and are difficult to degrade in the body. The long-term contact with these substances by humans can offset the low-affinity effects of estrogen receptors and cause malignant damage. There are also toxic chemicals that indirectly influence the function of the reproductive organs by affecting the function of non-reproductive systems, or altering the levels of hormone-binding proteins in the blood, or inhibiting the production of hormones. For example, polychlorinated biphenyls can inhibit the synthesis of maternal thyroxine and block resistance. Delayed fetal development; and ethylene estrogen and blood estrogen binding globulin affinity than estrogen lower, its free form increased, and thus easier to enter the cell, play biological rejection of 3 endocrine disruptors endocrine disruptors refers to the exogenous Chemical substances that mimic or block the action of endogenous hormones and even trigger abnormal target cell responses. Estrogen or androgen-like chemicals include: polychlorinated biphenyls, phthalates, certain Insecticides, phytoestrogens, and certain industrial wastes are widely distributed in workplace families, public places, and even hospitals. Studies have found that exposure to estrogen or androgen-like chemical pesticides can lead to impaired fertility in organ development and even hermaphroditism. Other studies have shown that exposure to estrogen-like pesticides can increase the incidence of breast cancer in women, precocious puberty, and menopause. The classical substance for the early endocrine disruptors is the well-known insecticide DDT. It was successfully synthesized in 1938, 1950. Widely used in the world, but later found that it seriously affected the reproductive function of wild animals and was banned in 1972. Ironically, the development of DDT was successfully won the Nobel Prize in Chemistry in 1948, but it was discovered two years later. It should be noted that it is toxic to the reproductive system. Although DDT has been banned for up to 26 years, it is still one of the planet's public hazards. Studies have shown that DDT pollution is one of the causes of the decline in semen quality in men around Apoka Lake, Florida, and the decline in the number of American vultures is also associated with the consumption of fish contaminated with DDT. For women, exposure to DDT during pregnancy can cause infants. The loss of weight and the shrinking of the skull.

Interfering substances, which are widely used in the manufacture of animal parts for automotive parts, plastic bags, beverage bottles, and can liners, show that Phthalates inhibit ovulation and cause abortion and birth defects in rats, but the impact on human reproductive function has not been reported. This may be because the study has not been conducted yet, and it may be related to the article that journals are reluctant to publish reports that Phthalates has no effect on female reproductive function. DES is a synthetic estrogen and is also an endocrine disruptor. Before the 1970s, it was widely used to prevent pregnancy loss and pregnancy complications. In 1971, it was banned because it was found to induce vaginal cancer. In addition, it has been found that DES is associated with menstrual disorders, breast cancer, ectopic pregnancy, premature birth, and infertility. Phytoestrogens are widely found in leguminous vegetables and cereals. Studies on their role as endocrine disruptors have shown that they are large. Rats and sheep have a negative impact on fertility, but there are still controversies about the role of humans. Studies have reported that phytoestrogen can reduce the incidence of uterine cancer and breast cancer, and alleviate the incidence of hot flashes in postmenopausal women. On the contrary, some studies have shown that it can lead to menstrual cycle disorders and precocious puberty caused by the contradictory results. It is unclear what may be different from the amount of edible plant estrogens and the research sample is too small. 4 Heavy metals such as lead, mercury, cadmium, and magnesium are harmful to the reproductive function of humans, wild animals and experimental animals in the United States. It is estimated that 42 million people consume excessive amounts of lead through drinking water, while lead in excess of 52 in interior paint exceeds the standard. For humans, lead can cause miscarriage, premature birth, or fetal death. Human exposure to mercury includes organic mercury and mercury. Inorganic mercury The three organic mercury compounds are the main components of the fungicide. Elemental mercury is used as a catalyst for dental fillers, thermometers, batteries and chlorine compounds. Inorganic mercury is mainly found in electrical fungicides and some illegal skin lightening agents. Frost. The above three forms of mercury are all harmful to humans. For women, organic mercury can cause miscarriage and infant birth defects; elemental mercury is mainly caused by menstrual disorders or amenorrhea; human exposure to cadmium mainly occurs in metal welding and soldering, housing, mining and Pottery and other industrial production processes. In addition, the consumption of fish and smoking are also important ways of ingesting cadmium. Cadmium poisoning can cause lung dysplasia in rats. When severe, it can trigger neonatal respiratory syndrome and neurological development disorders, which may be related to the reduction of cadmium and the generation of hCG during pregnancy. Decreasing the amount of oxygen the mother supplies to the fetus through the placenta. However, reports on the effects of cadmium on human reproductive functions have not yet seen human intake of magnesium primarily through diets such as cereals, cloves and tea. A small amount of magnesium is necessary for human health, and excessive magnesium can cause significant damage to the mouse's reproductive system. Reports that humans have not yet seen adverse effects 5 Organic solvents Organic solvents are widely used in electronics, pharmaceuticals, dry cleaning, painting, manufacturing Glue, drawing all fields and laboratories. Animal experiments and human data have proven that many solvents we know well, such as tetrachloroethylene (repellent wax), toluene xylene, and styrene can cause harm to the reproductive system. Perchloroethylene reduces the body weight and survival rate of rats and causes the fetus to melt it. May increase the possibility of infertility and miscarriage in women; toluene can cause animal fetal weight loss, skeletal growth retardation and female miscarriage; xylene is more harmful, and rodents can ablate the fetus, lose weight, develop retardation, maternal pregnancy Decreased levels of ketones and estrogens, suppression of ovulation, and disorder of the reproductive cycle; in the human body, it leads to miscarriage or teratogenic teratogenesis; styrene can prolong the estrous cycle of rats and cause stillbirth, and can also disturb women's normal menstrual cycle.

A recent study investigated the exposure of 281 infertile women to organic solvent chemical dust and pesticides. They all have infertility history caused by ovulatory disorders from 1 to 19 years, and the average infertility period is 4 years. Studies have shown that exposure to organic solvents and pesticides can significantly increase infertility rates. Despite the lack of dose and time parameters and the inability to exclude deviations from the subject's suggestive recall, the above results are sufficient to show that organic solvents can adversely affect our reproductive system. 6 Other industrial compounds Many chemicals produced in the production process are The workshop was filled and eventually entered the atmosphere where we lived. Although few studies have been done, there is already evidence that such substances are potentially harmful to the reproductive system. For example, the conventional dental disinfectant, vinyl oxygen, can cause teratogenicity, stillbirth, and abnormal pregnancy in rats. It can also be related to female abortion.

4 Vinyl cyclohexene and its diepoxide compounds are produced during the production of synthetic rubber, insecticides and fire extinguishing agents. The former can break down the primary follicles of mice and induce granulosa cell tumors; the latter destroys the primary follicles of rats, alters protein synthesis, and increases the expression of apoptotic genes. The effects on female reproductive function are unclear, mainly because women are very Less work in its production environment When bleached pulp is used to produce pesticides and incinerate chlorine-containing waste, dioxins are released into the environment. Because of its extremely slow biodegradation, it can exist in the environment and food chain for a long time, and accumulates in adipose tissue, which can destroy multiple organ systems and is one of the strongest chemical poisons. Embryonic and lactational exposure to two mouth-mouthing pups of estrous cycle changes, pregnancy rates decline, abnormal vaginal and external genitalia development, ovarian weight loss 1/4, endometrial cystic hyperplasia can also change the hormones in monkeys Levels, which lead to pregnancy failure and endometriosis, have little impact on the female reproductive system. An explosion in an Italian chemical plant in 1976 led to a second survey of the spread of the 5th, showing that the two guilty of the mouth did not alter the miscarriage rate of the women in the region. The genetic abnormalities in the cells and the birth defect rate were not universal, and they lacked real scientific evidence, such as hormones in the body. Level and quantification of ovarian function.

Koninckx et al. pointed out that the incidence of endometriosis in Belgian women ranks first in the world as the most polluted area in the world. This report suggests that the pathogenesis of endometriosis may be related to the second group of Eukotoxin, and it was investigated that 44 of the women with endometriosis infertility were found to have positive blood levels of 18%. On the other hand, only the infertile women with fallopian tube lesions were positive for blood test. This result shows that although the concentration of Dioxin Yingkou is not related to the severity of endometriosis, Dioxin may be one of the causes of endometriosis. Unfortunately, the sample size of the study is small, so the next exact conclusion is too early.

In the endometriosis model, two mouths of Eukhimectin can interfere with progesterone-mediated expression of matrix metalloproteinases and enhance endometrial immune cells to secrete cytokines. These two cell-level mechanisms can explain hormone insensitivity and endogenous cytokine overexpression in patients with endometriosis, as evidenced by the effects of dioxins.

PCBs have been used in transformers and capacitors, as well as hydraulic fluids and adhesives. Although the United States and most western countries have banned use since the 1970s, there are still a large number of PCBs that have accumulated in the environment. Fish in contaminated waters is the main way for humans to come into contact with it, but its content in dairy products (especially cheese and butter) and pork beef is not low. Animal experiments have found that polychlorinated biphenyls can reduce progesterone levels in the body, stimulate uterine growth, prolong estrus cycles, and induce abortions. In humans, polychlorinated biphenyls are associated with stillbirths, infertility in fetal growth retardation, and short-term memory developmental defects in young mothers. Mothers of polychlorinated biphenyls contaminated with polychlorinated biphenyls have slightly higher levels of polychlorinated biphenyls in breastmilk and breastmilk before breastfeeding. Mothers and children were born with the body's polychlorinated biphenyls accumulating in the same way as the mothers's bodies. However, by the age of 11 the toxins in children have dropped significantly. This shows that the route of exposure of children to polychlorinated biphenyls after lactation has been eliminated. IQ was found in children. The highest concentration of children (n = 30) (editor's note: n represents the number of children), IQ was significantly lower than normal children (n = 21) and exposure to low-toxicity children (n = 127), and these children's language understanding and The concentration of attention is only 1/4 of normal children, and the development of text comprehension is at least two years later than normal children. The toxicity of polychlorinated biphenyls has not yet been clarified. It may be related to the reduction of serum thyroid hormone levels during the critical period of brain development and the direct toxic and side effects of timely neuron differentiation. 7 Pesticides, pesticides, and herbicides are commonly used in agricultural production. . Organochlorine pesticides, such as DDT and 1068 pesticides, can cause abnormalities in the estrus cycle of vaginal malformations, inhibited luteal function, implantation, and pregnancy failure. Organochlorine pesticides can be detected in human milk and adipose tissue. Some researchers believe that such substances can cause breast cancer, miscarriage, and premature labor. Since existing research is often based on small samples, ecological data, or indirect detection methods, research in this area still needs to further deepen the role of organic phosphorus pesticides. No animal experiments have shown that organic phosphorus can inhibit follicles Growth and development of oocytes, precocious ovarian precocity, lower blood levels of LH and progesterone, and herbicides can cause fetal poisoning, pseudopregnancy, ovarian deterioration, estrus growth, and ovulation. Chemical toxins present in the environment The influence of function is a new subject that has emerged in recent years. It is still in its infancy. Therefore, the above findings are still preliminary observations. There are still many deficiencies in the methodological science. For example, some scholars randomly divided research subjects into contacts. Group and non-contact groups, but did not consider that in the non-contact group, the population may not be exposed to the specific chemical toxins they studied but may be exposed to other chemicals harmful to the reproductive organs; Long-term cumulative effects; in addition, due to the species-specific differences in reproductive function between animals and humans, many The results can not be generalized to humans, some harmful chemical toxins in experimental animals, and non-toxic to humans, and vice versa. In the future, researchers in the obstetrics, gynecology, epidemiology, and basic sciences will need to collaborate to conduct large-scale surveys and use sensitive and reliable technologies to determine the chemical substances that are harmful to female reproductive functions in the environment so as to prevent them from interacting with the human body, especially the reproductive system. Damage.