And of course it is the . demand for drugs that fuels Mexican drug smuggling in the first place. Take, for example, the current heroin epidemic in the United States. It originated in the over–prescription of medical opiates to treat pain. The subsequent efforts to reduce the over–prescription of painkillers led those Americans who became dependent on them to resort to illegal heroin. That in turn stimulated a vast expansion of poppy cultivation in Mexico, particularly in Guerrero. In 2015, Mexico’s opium poppy cultivation reached perhaps 28,000 hectares, enough to distill about 70 tons of heroin (which is even more than the 24–50 tons estimated to be necessary to meet the . demand).
Air pollution involves the emission of toxic fumes into the air. Everyone in way contributes to air pollution in his/her capacity. Carbon dioxide is among the main pollutants of the air. This gas forms a big percentage of the gases that are emitted in many factories across China. Combustion of fossil fuels and deforestation greatly contribute towards the increased levels of this gas in the atmosphere. It is also emitted during any volcanic activity. It is a major contributor towards global warming. Most automobiles, air jets, and marine vessels also release fume to the atmosphere. Other pollutants include Aerosol sprays, nuclear fumes. Other dangerous gases that pollute the air include carbon monoxide and Sulfur dioxide. "Air pollution can cause acid rain, which occurs whenever sulfur dioxide combines with Nitrogen dioxide" (Hart 2006, p. 62).