Groundwater is different from surface water. It is known as the "life water" of human beings. Once it is polluted, it is quite troublesome to handle and it may take hundreds of years to deal with it. Nowadays, some enterprises inject deadly sewage directly into the ground through high-pressure wells in order to avoid investigation. For a long time, because of its own concealment and the fact that there are few groundwater pollution in life, typical malignant events occur, so groundwater pollution has not entered the public's attention. So what exactly is the status quo of our groundwater pollution?
Who is the culprit for 80% of the diseases?
Groundwater pollution in some cities
In 2011, the Ministry of Land and Resources carried out groundwater quality monitoring on 200 cities, and 55% showed a poor-very poor level. In 2012, the Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences launched a survey of surface water and groundwater quality across the country, involving about 80 densely populated areas, such as Poyang Lake in Jiangxi, Dongting Lake in Hunan, Taihu Lake in Jiangsu, and the Three Gorges Reservoir of the Yangtze River. . Surveys show that groundwater quality in many areas has not reached minimum water quality standards and is only suitable for agricultural irrigation.
In 2013, the China Geological Survey issued another report on ground pollution in China. The report surveyed 118 cities in China and 64% of urban groundwater was polluted. Although groundwater is a renewable resource, its renewal and self-purification are very slow. Once polluted, the environmental and ecological damage caused by it is often difficult to reverse for a long time.
80% of diseases are caused by drinking sewage
When man-made pollutants such as gasoline, petroleum, road salt, fertilizers, pesticides and other chemicals penetrate the groundwater, the water is poisonous and the water is unsafe and unsuitable for human use. This is groundwater pollution.
Regarding the relationship between groundwater pollution and disease occurrence, although there is no direct data in the country to prove it, cancer has been increasing year by year, and the argument that water pollution is one of the culprits has not been opposed. According to the Global Environment Outlook 4 released by the United Nations Environment Programme in 2007, 80% of the world ’s diseases are caused by drinking polluted water; half of the deaths of children are caused by drinking polluted water Yes, the cause of death includes cancer.
The human body has been drinking contaminated water for a long time and accumulated to a certain extent, which can cause various cancers throughout the body. In water pollution, some chemicals such as benzene are strong carcinogens. Long-term intake can cause leukemia, lymphoma, and skin cancer. And heavy metals contained in polluted water, such as arsenic, lead, cadmium, and manganese, can also cause cancer.
Invisible water crisis
Is the tap water we drink is groundwater?
It is understood that tap water sources are divided into surface water and groundwater. Surface water sources are the main sources of water in water plants. Taking Beijing as an example, Miyun Reservoir, Huairou Reservoir, and three Hebei reservoirs are Beijing's surface water sources. These reservoirs provide 60% of Beijing's water, while the other 40% use groundwater.
In fact, there is no so-called tap water that ordinary people drink from deep underground wells or surface reservoirs, because we are drinking "mixed water" of surface water and groundwater, in other words, we are drinking groundwater.
Some experts said that people do not need to worry about the quality of tap water, because whether it is surface water or groundwater, they must undergo various disinfection and sterilization treatments before entering the water distribution network.
First, the surface water purification treatment uses a combination of conventional treatment and activated carbon technology. In addition to conventional water treatment processes such as dosing, clarification, and filtration, a deep purification process using activated carbon adsorption and chlorination disinfection is used to further remove astringent, odor, odor, and various organic matter in the water; finally, production Fresh water that meets the national sanitary drinking water standards is sent to the urban water distribution network.
The water company has also established a water quality monitoring system for the whole process, which monitors the whole process of the water source water, factory water, pipe network water, and user terminal water to ensure that the quality of tap water meets national standards.
So how do we drink safe water?
As ordinary consumers, we have no way to control the pollution of water sources, nor can we supervise the treatment process of water plants, nor can we check the quality of commercially available bottled bottled water. So, what methods can you use to drink assured water?
Boil water. High temperature can deal with bacteria, but can not remove toxic inorganic substances such as heavy metals and sterilization by-products. Therefore, boiling water is only a necessary and inadequate condition for drinking water. If the water source is not pure, it is best to add other purification measures.
Water filters, water purifiers. Although the filtration system can filter bacteria in principle, if the filtered water purification products have always played a normal role, more attention should be paid to regular maintenance, such as replacing the filter element, checking whether the automatic drainage system is normal, and so on. It can also easily become a source of pollution if it is bought for a few years without inspection.
Bottled water. If you want to use a water dispenser for heating, try to buy a water dispenser that has a microcomputer control system that separates hot and cold water. The secondary pollution of the water dispenser is the source of many unqualified drinking water. If it is not possible to regularly clean the inside of the machine, it is better to use less.