In recent years, clinical practice in male clinics has also seen a decline in sperm quality leading to an increasing number of patients being seen for male infertility. Some of the causes of sperm quality decline are congenital or acquired diseases, while others are caused by some human factors in life. Among them, the following 10 factors have been proven in studies to have the greatest impact on sperm quality: (1) Food packaging and cosmetics The global decline in male sperm count over the past few decades may be linked to a chemical called phthalates. Phthalates are a class of chemicals that act as a softening agent. It is commonly used in toys, food packaging, vinyl flooring, wallpaper, cleaners, lubricants, nail polish, hair sprays, soaps and shampoos, and hundreds of other products. Studies have shown that phthalates can interfere with endocrine secretion, causing a reduction in the number of male sperm, low motility, abnormal morphology and, in severe cases, testicular cancer, making them the “culprit” for male reproductive problems. Among cosmetics, nail polish has the highest phthalate content. It enters the body through women’s respiratory system and skin, endangering the reproductive system of their future male children. Phthalates can also enter the body through food and water packaged in plastic containers, such as the inner coating of food cans, recyclable milk and mineral water bottles. Studies have shown that the higher the fat content of canned foods, the more susceptible they are to contamination, such as pork, anchovies, and sardines. Fetuses, infants and adolescent children are the most sensitive to it and the most vulnerable to health violations. To reduce the risk of phthalates to humans, it is usually best not to use Styrofoam containers to soak instant noodles and not to use plastic containers containing polyvinyl chloride to heat food in the microwave oven. The correct approach is to put the food into heat-resistant glassware or ceramic utensils to heat. (2) car exhaust car exhaust contains a large number of harmful substances, such as sulfur dioxide, carbon dioxide, etc.. Prolonged exposure to these substances will cause cumulative damage to the human body, which not only affects reproductive health, but may also increase the incidence of tumors and other diseases. The most serious is that the dioxins contained in car exhaust are strong environmental endocrine disruptors that can cause changes in the morphology of the testicles, reduce the number of sperm and reduce sperm production capacity in men. (3) Smoking and alcohol Smoking has always been a major enemy of health, and the impact on semen is equally obvious. Foreign studies have long shown that smokers have significantly lower semen quality indicators, higher sperm malformation rates, and an increase in the number of white blood cells in semen compared to non-smokers. The nicotine and polycyclic aromatic hydrocarbons produced in tobacco cause testicular atrophy and altered sperm morphology. Alcohol has a direct effect on both the human liver and male testes. Studies have found that patients with chronic alcoholism develop testicular atrophy, leading to decreased semen quality. Therefore, men must avoid regular excessive alcohol consumption. (5) Estrogen Estrogen can have significant effects on the male reproductive system, including affecting the level of androgens, triggering changes in testicular tissue structure, causing testicular cancer, reducing the number of sperm in semen, causing gynecomastia, and leading to endocrine disorders. Short-term use of estrogen-containing drugs by men does not significantly affect the reproductive system, but long-term exposure to estrogen-containing items in life can cause greater harm to reproductive health. For example, some men casually use female cosmetics in their skin care. Some of these cosmetics developed specifically for women contain certain estrogens, and long-term use can damage male reproductive health and cause hypogonadism. (6) Trace elements and amino acids Trace elements related to male fertility mainly include zinc, selenium, calcium and magnesium. Zinc is an important element in the reproductive system, lack of zinc will affect the development of male reproductive organs and secondary sexual characteristics during puberty, reduce the mobility of sperm, weaken the body’s immune function, making men vulnerable to prostatitis, epididymitis and other infectious diseases. And selenium deficiency will increase the concentration of peroxide in the body, causing damage to the male reproductive system and testicles. Therefore, men should usually eat more foods that are high in zinc and selenium, such as milk, corn, black rice, black beans, etc. Insufficient amino acids not only lead to impaired sperm production, but also seriously affect sperm antigenic activity. (7) Temperature High temperatures can produce damage to the testes, but exactly how high and how long exposure to such temperatures will affect the testes is still debated in the academic community. In animal studies, the fertility of males was reduced after being exposed to 38.5°C for 55 minutes. In reality, men should try to avoid staying in hot environments for too long, such as taking sauna baths and soaking in hot water. (8) Drugs Drugs such as anti-cancer, hormones and antibiotics can impair male gonadal function, causing a decrease in the quantity and quality of sperm, or by affecting the endocrine function of the gonads, leading to sexual dysfunction. The effect of drugs on male fertility is influenced by the type of drug, the dose, the course of treatment, the age of the patient and other factors. Generally, the higher the dose of drugs used, the longer the course of treatment, and the younger the patient, the more serious the damage to fertility and the longer the time needed to restore fertility. At present, the society is flooded with sexual health products, some of which contain sex hormones or similar ingredients that may affect the normal spermatogenic function of the testicles, and unmarried infertile people should be extra careful when choosing. (9) Noise With the development of modernization, the impact of urban noise on health has become more prominent. Noise is a kind of environmental pollution. In recent years, some experts have proposed the theory of “environmental hormones”, pointing out that there are chemicals in the environment that can affect the endocrine function of the human body like hormones, and noise is one of them. It will make the human endocrine disorder, resulting in abnormal semen and sperm. Prolonged noise pollution can cause male infertility; for women, it can lead to miscarriage and fetal abnormalities. Radiation Radiation has been determined to have a definite effect on human health. Large doses of radiation can cause changes in testicular tissue structure, increase sperm malformations, and decrease sperm count, sperm density, and other important indicators. However, there are no definite research results on whether small doses of radiation can cause infertility. There is a great controversy in the academic community whether the electronic devices we use everyday, such as cell phones and computers, can cause infertility. Therefore, men should usually try to reduce contact with radiation sources, but there is no need to overstress. (10) Drugs There are many people who take drugs in China, and some drugs, such as marijuana and cocaine, have an effect on semen quality. Marijuana can lower the level of androgens in the blood and sperm density, leading to male breast development; cocaine can cause a decrease in sperm density. Sperm quality is a major issue related to human survival and reproduction. For these factors, on the one hand, we should take a high degree of vigilance, timely attention and avoid; on the other hand, we should also call on all forces of society to improve our living environment.