Scientists from the State University of New York argue that even small levels of lead in children's blood can lead to the development of cardiovascular diseases.

It turns out that lead affects the strength of vascular resistance, which, when raised, leads to hypertension. Also lead in the blood reduces the levels of the hormone aldosterone, which helps regulate blood pressure.

Previous studies have indicated a relationship between levels of lead measured at 2 years, with increased vascular tension at the age of 9.5 years.

In the new study, the researchers collected data on 140 children aged 9-11 years who solved difficult tasks on the computer. They examined the work of the heart, also measuring the blood pressure of children under stress. Total peripheral (vascular) resistance - the ratio of blood pressure and heart function.

Researchers compared levels of lead in the blood of children with cardiovascular parameters. It turned out that the amount of metal correlated with an increase in vascular resistance in response to stress.

It was also found that lead levels were relatively low - less than 10 micrograms per deciliter. The highest of them was only 3.8 ?g.

Explaining this connection, the scientists determined that the children had increased activity of the sympathetic nervous system during rest and decreased this activity while working at the computer.

It is the sympathetic nervous system that is responsible for the heart rate and the dilatation of the blood vessels. This reaction is typical for stress, but with prolonged exposure it can harm the body.

Scientists believe that lead increases the excitation of the sympathetic nervous system during rest, because of which all reactions are weakened (worn out) under the influence of stress.

Also, lowering the level of the aldosterone hormone due to lead concentrations further slows down the reactions of the sympathetic health system. Sumy. Ua.