in a district of the provincial capital, 1 The small courtyards of the tenants have planted different kinds of vegetables. Reporter Zhang Zhong took 
the lead in the car's tail gas could cause soil pollution. Reporter Zhang Zhong takes
a lot of people are keen to grow vegetables on the balcony. (information film)
Li Yunxiang (Dean, Professor of Shandong Agricultural Administrators College, deputy head of the agricultural expert advisory group of Shandong province)
now, some residential green belts and idle land are reclaimed into vegetable gardens, " "Urban vegetable garden" is heating up. Some people say that it is not impossible to make this happen. It is more important to make full use of it. Is it true?
with the growing popularity of family cars, almost all residential communities have become parking lots, and the pollution caused by automobile exhaust is becoming more and more serious. The so-called automobile exhaust pollution, mainly refers to the diesel, gasoline and other vehicle fuels with additives and impurities in the incomplete combustion of some harmful substances. According to the relevant information, a car annual emission of harmful exhaust gas is 3 times the weight of the car, which contains more than 100 kinds of harmful substances, mainly including solid suspended particles, carbon monoxide, nitrogen oxides, hydrocarbons, heavy metal lead and other harmful components.
studies show that the main pollution sources of soil on both sides of the highway are the exhaust of the motor vehicles, the oil discharge, the wear of the brakes and the wear of the tires. The concrete manifestations are mainly heavy metal pollution in the soil. The heavy metals in the contaminated soil are mainly toxic mercury, cadmium, lead and arsenic, followed by the toxic general toxicity. Zinc, copper, nickel, cobalt, tin and so on, and the most typical heavy metal is generally recognized as lead in automobile exhaust.
Research on automobile exhaust detection in residential areas has not been paid attention to, but the problem of automobile exhaust pollution on both sides of the highway can be used for reference and analogy. More than 60% of the lead in the city's atmosphere comes from the burning of leaded gasoline, and a considerable portion of the lead particles from the car's tail gas are deposited in the 50 meters of the roadside, with a small amount extended to a range of about 100 meters. The greater the volume of traffic, the greater the concentration of lead pollution.
regulations on the production and operation of heavy metals of heavy metals in municipal sludge
green food clearly stipulate that the farm manure should be fully decomposed and harmless, and the fertilizer should be restricted as far as possible, and the use of municipal sludge is prohibited. However, the sludge of some cities is often used by residents as organic fertilizer without removing heavy metals and other harmful substances.
although the content of organic matter and nitrogen and phosphorus in sewage treatment plant and urban and suburban river sludge is abundant, it has been found that heavy metals in municipal sludge have exceeded our agricultural standards. Zinc and copper are the most important heavy metal pollutants in several cities investigated, which exceed the standard in most cities. It is not suitable for the planting of vegetables and fruits. In order to prevent the pollution of heavy metals to plants, in the application of municipal sludge as fertilizer, the harmless treatment should be carried out first and the harmful heavy metals should be removed. At the same time, the pH value of the soil, the allowable content of heavy metals in the sludge and the number of fertilized times of the year should be stipulated so that the pollution of heavy metals can be reduced to a certain degree, so as to ensure that the pollution of heavy metals can be reduced. The quality of agricultural products.
there is a safety hazard in livestock and poultry dung
for the safety and growth of self growing vegetables, some residents do not choose fertilizer when planting vegetables in the community, and collect organic manure through various channels to make the surrounding environment inaccessible, mosquitoes and flies breeding, and even some residential owners make a noise for this. Contradictions affect the neighbourhood. It is not known that the organic manure which has not been treated without decay and innocuous treatment can not only fail to promote the safety of food, but also has a greater safety hazard.
first, livestock and poultry manure contains a large number of harmful microbes, pathogenic bacteria, parasites and parasitic eggs, such as the sewage from livestock farms, containing 330 thousand Escherichia coli and 690 thousand Escherichia coli per milliliter, and more than 190 Ascaris eggs and more than 100 line worm eggs in 1000 milliliters of sediment pool. Some pathogens are pathogenic bacteria of human infectious diseases. Pathogens in feces can be transferred to vegetables grown through soil and water and infectious diseases.
next, with the scale and intensive development of the aquaculture industry, the use of feed and veterinary medicine is becoming more and more extensive. Some feed or veterinary drugs contain copper, zinc, iron and other elements, many are not absorbed and used, and excreted with feces. Many metals not only pollute the water environment and soil environment, but also transfer the soil to the vegetables grown by residents, which can harm human health through the food chain.
waste battery fluorescent tube is a pollution source
battery mainly includes one time battery, two battery and battery. One time battery mainly includes basic batteries such as No. five and seven. The two battery is mainly rechargeable battery. It contains heavy metal cadmium and nickel. It is widely used in mobile phone, electric tool and electric power. The battery refers to the lead-acid battery, which contains acid and heavy metal lead, which is mainly used in automobile, electric bicycle, communication standby power and emergency power supply. The harmful substances in dry cells are mainly mercury and other heavy metals such as manganese, cadmium, lead and zinc. An abandoned five battery can make a square meter of land lose the value of farming, and a button battery can pollute 60 liters of water. The mercury content of alkaline dry cell in China is as high as 1%-5%, and neutral dry cell is 0.25%.
China is a country of dry battery production and consumption, with annual output of about 14000000000, ranking first in the world and consumption of about 7000000000, with an average of five dry batteries per person per year. Much of this production is lost in the environment.
the harmful substances in the battery are mainly mercury, lead, nickel, zinc and other metal elements. In the green space and corner of the community, the batteries that are discarded are often found. As time goes on, heavy metals and harmful substances in the battery will enter the soil, water and atmosphere, causing serious environmental pollution. After the waste battery was buried in the soil, the shell was destroyed and the content was exuded through mechanical wear and corrosion. The internal heavy metals, such as lead and cadmium, were released into the soil and absorbed into the plant through the root of the plant to enrich the heavy metals in the roots and stems of the plants.
the inner wall of fluorescent lamp is coated with luminescent material, and mercury vapor and argon are contained in the tube. After the random discarded fluorescent tube is broken, the mercury vapor in the tube will be emitted to pollute the air, soil and water. If the vegetables are grown, the volatile mercury or the mercury in the soil can be absorbed by vegetables and into the roots, stems and leaves of the vegetables.
the statistical analysis of construction materials such as building garbage
building type of brick concrete structure and full cast in place concrete structure, it is found that five hundred or six hundred tons of construction waste will be produced in every 10000 square meters of construction projects. More than 40 million tons of construction waste is produced in China each year, which is mainly residue and scattered. Mortar and concrete, scrap metal, waste decorative materials, and various packaging materials and other wastes. The site selection of most urban building garbage dumps is very arbitrary to a large extent. In addition, the green belts in many communities are often building garbage.
the harmful substances in construction waste (including polycyclic aromatic hydrocarbons released by paint, paints and bitumen in urban construction waste) infiltrate into the soil by landfill leachation to absorb or be synthesized by the plant roots (polycyclic aromatic hydrocarbons as strong carcinogens); in addition, construction waste is heavy. The content of heavy metals is higher. Under the action of many factors, the content of heavy metals in soil increases, which will increase the content of heavy metals in plants.
balcony planting vegetables do not apply organic fertilizer
nowadays, balcony planting vegetables is favored by more and more urban people. Experts say balcony planting is a cool, green and healthy way of life. It should be encouraged.
planting vegetables on the balcony, using plastic foam boxes for soil or hydroponics, can usually be well guaranteed in the soil and water, and it is easy to control once the diseases and pests occur. Balcony vegetables have a good effect on purifying indoor air and improving indoor humidity. Vegetables are grown on the balcony, leafy vegetables are more suitable, such as lettuce, Pakchoi, rape, water spinach and so on. Cucumber and tomatoes can also grow, but their vines are more difficult to fix. It's also good to grow garlic.
planting vegetables on the balcony should be noted that no organic fertilizer is applied and plants with too much aromatic smell are not planted to prevent indoor odor. In the water culture way, the deployment of nutrient solution needs to be accurately handled.
in addition, while strengthening practice, the public should learn the practical knowledge of planting vegetables, and arrange different vegetables according to the different conditions of the balcony and the health of the family.
health food certification needs verification and inspection of
health food including non polluted food, green food and organic food. The production of these foods has a very important link. Check the technical specification, and carry out on-site verification and environmental sampling inspection by relevant departments.
the technical specification for the investigation of environmental quality of green food producing areas clearly stipulates that water quality, soil environment and atmospheric environment are the primary and basic conditions for certification. It is necessary to investigate the natural environment, soil type and environment background value, pesticide and fertilizer application in the area of product origin, especially whether the application of multi fertilizer, rare earth fertilizer, organic mercury and organic arsenic, sludge and so on in the producing area, whether the foreign organic manure and the origin of soil and soil are introduced in large quantities; Sewage irrigation and water quality and so on.
atmospheric environment, garbage multicomponent fertilizer, guest soil, sludge and so on are closely related to the safety of vegetables grown in the plot.