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The number of children exposed to environmental pollution grows as industrial and agricultural activities increase.
Smog-type air pollution comes from the combustion of sulfurous fossil fuels, particularly coal. It occurs mainly in winter and is characterized by a mixture of sulfur dioxide and respirable particles (fumes). Since sulfur dioxide is usually absorbed by particles, the total pollutant load is measured, by agreement, as total suspended particles (TSP).
On smog days when the PST concentration exceeds the level of 250 mg/m3, there is an increase in asthmatic reactions and bronchitis. In children, lung function is altered with concentrations higher than 200 mg/m3 and a quarter of the most sensitive children are affected four times higher than the rest of the children (experiences in Mexico and Rio de Janeiro are very expressive). ).
From 100 mg/m3, respiratory symptoms increase inexorably. Studies carried out in the United States indicate that school-age children cough more and the frequency of bronchitis and asthmatic wheezing increases when the level increases from 40 to 120 mg/m3.
There is great concern about the increase in asthma and deaths related to this disease in the young population. Environmental pollution may be, perhaps, an important culprit.
There is photochemical smog that occurs mainly in summer. With sunlight, nitrogen oxides react with the volatile hydrocarbons in the gases produced by the exhaust pipes. The ozone and nitrogen dioxide formed by this reaction cause photochemical smog.
Ozone is a powerful oxidant, highly chemically reactive, susceptible to damaging cell membranes. Inhaled ozone reacts quickly with the cells, liquids and tissues that border the respiratory tract, limiting the mechanical functioning of the lungs due to the cellular, structural and functional lesions they cause.
Ozone can affect the lungs of healthy children, asthmatic children and people with bronchitis at concentrations somewhat different from those that normally prevail (0.1 – 0.2 ppm).
The effects of photochemical smog (ozone and nitrogen dioxide) are to aggravate respiratory disorders (asthma, emphysema, bronchitis and hay fever).
In South American populations most affected by photochemical air pollution, more than 2 million children out of a population of 81 million suffer from chronic cough each year due to this cause.
Acid aerosols that form when photochemical pollution combines with the combustion products of fossil fuels can have unfavorable effects on respiration.
More than two-thirds of the world’s families live in developing countries. Frequently in rural areas where biomass (forests, animal excrement and agricultural waste) is the main fuel for cooking and heating. These fuels emit harsh fumes that are harmful to health: hydrocarbons, carbon oxide and nitrogen oxide.
Wood releases 50 times more pollutants than a gas stove used to prepare the same food.
A study in Ladakn, Nepal, shows that household air pollution is the main cause of carbon oxide inhalation and reduced lung function. This is because they burn wood and dried yak dung for heat and cooking in small, poorly ventilated rooms. During winter, when the outside temperature drops to -30º C, families spend long periods of time confined to rooms whose air is heavily polluted.
Nitrogen dioxide is of particular concern. It accumulates in the air produced by the high-temperature combustion of gas or oil heating appliances or stoves. Domestic exposure to this gas has been proven to increase respiratory pathology.
The nitrates that accumulate on the water surface and in the water table come mainly from the use of nitrogen fertilizers in agriculture, nitrogen waste from livestock and the dairy industry. Nitrates are one of the causes of methemoglobinemia in infants. To avoid this, the WHO has set the standard value of 10 ppm as nitrogen (equivalent to 50 mg/l as nitrates) in drinking water.
Nitrates have also been suspected of causing fetal malformations and, in animal experiments, nitrates and their derivatives – nitrosamines – have been shown to cause lesions in the central nervous system of the fetus. In Mount Gambier, Australia, an excess of congenital malformations was observed that was associated with an increase in nitrates in certain sources in the city.
Pesticides comprise a series of chemical compounds capable of killing animal (particularly insects) and plant parasites, specifically called rodenticides, nematocides, insecticides, herbicides or fungicides. They are toxic substances that we deliberately add to our environment.
They are also used mainly in developing countries to control vectors and intermediate hosts of diseases such as malaria, onchocerciasis and schistosomiasis.
It is estimated that pesticides are responsible for approximately 100,000 deaths each year, with young children being the most affected due to inappropriate storage of pesticides (especially in sugary drink bottles) and children’s relentless exploration of their living space.
Infants may also be exposed to concentrations of pesticides in breast milk. It was observed in Turkey in the 1950s that wheat seeds prepared with hexachlorobenzene were mistakenly sold for food in several cities and, as a result, numerous deaths occurred secondary to acquired cutaneous porphyria in breastfed infants.
Other studies have shown a high frequency among the children of agricultural workers and work carried out in India and the United States suggests that exposure to pesticides is embryotoxic and fetotoxic, therefore responsible for high rates of
abortions during the first trimester. This could mask the possible extent and frequency of fetal lesions seen at birth.
Heavy metals – lead, cadmium, mercury and arsenic – are widely used in industry. Many industrial waste and exhaust gases from vehicles that use leaded gasoline contain heavy metals. These pollutants accumulate and persist in the environment.
Heavy metals are taken up by biological organisms and can accumulate in certain tissues. For example, lead and cadmium accumulate in the skeleton, teeth and kidney; lead and mercury accumulate in the brain and central nervous system; Arsenic accumulates in the skin, hair and nails.
Organic heavy metal compounds can produce serious toxic effects. Methylmercury has deleterious effects on the brain. These effects were manifested in the tragic Minamata Bay episode in Japan during the 1950s. A factory dumped liquid industrial waste containing mercury into a local river and along the coast.
This heavy metal, after methylation by sedimentary organisms, entered the aquatic food chain and reached high concentrations in fish that were consumed by the inhabitants. Methylmercury caused serious brain damage and rare behavioral disorders in both humans and cats that had eaten the contaminated fish.
There was a high frequency of cerebral palsy in children and infants. It has been shown that the ingestion of methyl mercury is capable of harming the neuro-psychological development of children.
The frequency of occupational lead poisoning increased with the Industrial Revolution; The frequency of abortions, stillborn and premature children has been very high among workers exposed to lead.
Lead poisoning has decreased greatly. Concerns center on the adverse effects on the central nervous system of young children exposed to low concentrations of lead in the environment.
Lead (PbS) concentration reaches its highest level around 2 years of age, due to children putting their hands in their mouths during early childhood. The risk increases because intestinal absorption of lead is greater in children than in adults. It is debated whether exposure of young children to environmental lead at concentrations below 20-30 mg/100ml affects their mental development.
Research carried out in Port Pire (Australia), Boston and Cincinatti has proven that lead concentrations of 10-30 mg/100ml are associated with neuro-psychological development disorders. This aspect is very important for health policies.
In developed parts, lead is progressively eliminated from gasoline and levels in canned foods have been substantially reduced.
The Chernobyl disaster and others like it have seared into our consciousness the massive potential dangers to public health.
The health consequences resulting from the accident will not be known for a few years. We know, however, that the incidence of cancer in people exposed to radiation since childhood continues to increase 50 years later among atomic bomb survivors.
The International Agency for Research on Cancer has estimated that the increase in the frequency of leukemias in children in the Chernobyl region will increase between 1% and 6%.
The world’s wealthy urban populations increasingly live under an electromagnetic cloud. At the end of the spectrum of electromagnetic radiation of weak non-ionizing energy is the band of long-wavelength and low-frequency radiation. This band includes radio frequency and microwaves – used in radio communications, heat sealing, radio broadcasts and cooking.
Disturbances in the chick embryo and fetal losses in the pregnant rat have been experienced.
Living near high-voltage power lines has been shown to increase the risk of cancer, particularly leukemia.
If this risk of cancer is demonstrated, it could have great significance in terms of public health, since the future is to replace electrical energy instead of other more polluting energies.
