The main sources of environmental pollution

The main sources of environmental pollution are as follows:

(1) exhaust smoke, exhaust gas, waste water, waste residue, and noise emitted from factories;

(2) exhaust smoke, exhaust gas, noise, dirty water, and garbage emitted from people's lives;

(3) exhaust and noise emitted from means of transportation (all fuel-fired vehicles, ships, and airplanes, etc.);

( 4) Water runoff from irrigated farmland where chemical fertilizers, pesticides, herbicides, and other chemicals are used in large quantities;

(5) Waste water from mines and waste residues;

(6) Noise from machines, electromagnetic radiation, and carbon dioxide pollution; the main pollutants in the air are sulfur dioxide, nitrogen oxides, particle-like pollutants, and acid rain.

Extended information:

p>Environmental pollution is the result of various polluting factors themselves and their interactions. At the same time, environmental pollution is also influenced by social evaluation and has a social nature. Its characteristics can be summarized as follows:

1) public harm, environmental pollution is not affected by the region, race, economic conditions, all victims.

2) latent, many pollution is not easy to detect in time, once the outbreak of serious consequences.

3) long-lasting, many of the continuous impact of pollution for a long time, jeopardizing people's health and life, and is not easy to eliminate.

The environment is a complex system, must take into account the integrated effect of various factors. From the traditional toxicological point of view, the simultaneous existence of a variety of pollutants on people or organisms have the following effects:

①Single role, that is, when some organs in the organism is only due to the harm that occurs in a certain component of the mixture, not due to the pollutants *** with the same role and deepen the harm, known as the pollutant's separate role.

② additive effect, mixed pollutant components of the body of the same organ of the toxic effects of each other similar, and biased in the same direction, when this role is equal to the toxic effects of the pollutants when the sum of the role of the pollutants, known as the additive effect of pollution. Such as the atmosphere between sulfur dioxide and sulfuric acid aerosol, chlorine and hydrogen chloride, when they are in low concentrations, the joint toxic effect is additive, while in high concentrations do not have additive effect.

3 multiplying effect, when the mixed pollutant components of the body's toxic effects more than the sum of individual toxic effects, known as multiplying effect. Such as sulfur dioxide and particulate matter, nitrogen oxides and carbon monoxide, there is multiplication.

4 antagonism, when two or more pollutants on the body of the toxic effect of each other offset part or most of the time, known as antagonism. For example, animal experiments have shown that the toxicity of methylmercury may be inhibited when 30 ppm of methylmercury is present in the food and 12.5 ppm of selenium is present at the same time.

References:

Baidu Encyclopedia- -Environmental Pollution