1. Endemic diseases
Endemic venereal disease refers to a disease with strict local characteristics. Endemic diseases are widely distributed in China, with many patients and threatened people.
Endemic fluorosis is a chronic toxic endemic disease caused by long-term fluoride intake in high fluoride environment, which mainly affects hard tissues such as bones and teeth. The early lesion is that dental fluorosis destroys the developing enamel, and the continuous development can cause bone changes, which are manifested as low back pain and blocked joint activities. In severe cases, the bones are deformed, disabled or even paralyzed, and life cannot take care of itself.
It is reported that about 60 million people in China's rural water supply exceeds the hygienic standard, and about 20 million people suffer from endemic dental fluorosis and skeletal fluorosis.
Type Ⅲ third-degree dental fluorosis with skeletal fluorosis
1994, the government of China officially listed arsenic poisoning as an endemic disease for prevention and control, and conducted a nationwide survey. Up to now, at least 17 provinces and regions have found arsenic poisoning in drinking water. Drinking water with high arsenic content for a long time will cause arsenic poisoning, lead to skin cancer, blackfoot neuralgia, vascular injury and gangrene, and increase the incidence of heart disease.
In recent years, the drinking water quality standards of the World Health Organization, the United States, Japan, Canada and other countries have reduced arsenic from 0.05mg/l to 0.01mg/L. On July 27-30, 2003, the Chinese Medical Association reported at the Fifth National Academic Conference on Endemic Diseases held in Nanjing that according to the water arsenic standard of 0.0 1mg/L of the World Health Organization, the exposed population in arsenic poisoning areas in China was as high as 65,000.
2. Environmental endocrine disruptors and their effects
The harm of chemical substances to drinking water pollution is different from that caused by microorganisms. The main health hazards are the harmful effects caused by long-term exposure, especially the accumulated poisons and carcinogens.
In recent years, organic pollutants in water have aroused widespread concern. There are many kinds of organic matter, thousands, and more than 1000 kinds are added every year. Synthetic organic matter is stable in form, and it takes years or even decades to degrade into harmless substances in the environment, so it will remain in the environment. In the process of biodegradation, these compounds will be enriched in the body, which will greatly increase the concentration in the body and be transmitted through the role of biological chain. Many synthetic organic compounds have mutagenic, teratogenic, carcinogenic and toxic effects, which are potentially harmful to health. Compared with natural organic substances in water, they are more harmful to public health.
1995, students in Minnesota, USA, discovered deformed frogs and posted their photos on the Internet. Subsequently, similar reports appeared in 54 of the 87 counties in the state, which shocked the world. From 2000 to 200 1 year, a large number of three-legged frogs were also found in the ditches in the southern suburbs of Tianjin and Chaoyang City, Liaoning Province. Studies have shown that it is caused by a class of substances called environmental endocrine disruptors.
Environmental endocrine disruptors will not only have an impact on creatures living in water, but also the most obvious harm to human beings is the decline of reproductive function. In the last 50 years, the number of male sperm in the world has decreased by 50%, and the proportion of infertile or infertile couples has reached 10%- 15%. Analysis of semen quality test report of adult fertile men in China during1981-199616. The published data also shows that the number of male sperm has decreased by nearly 30%. The primary cause of all this is environmental endocrine disruptors.
It is reported that endocrine disruptors have been detected in the blood of people in many parts of the world. The sources of organic pollutants in the body are complex, but the main absorption routes of endocrine disruptors are food and drinking water. The research shows that some organic substances detected in the blood of 50 people in southwest Chongqing are highly consistent with the organic components of drinking water in this city. Phthalates were detected in 50 blood samples, which have been internationally recognized as environmental endocrine disruptors.