Exhaust gases and industrial emissions saturate urban air with greenhouse gases, toxic sulfur and nitrogen oxides and fine particles of various chemical nature, mainly products of combustion of hydrocarbons, ash and soot, as well as crystals of mineral salts.

Researchers from the University of Cincinnati and the Children's Hospital of Cincinnati confined themselves to studying the harmful effects of particles smaller than 2.5 microns in diameter (PM2. 5). The suspension of these particles in the air worsens visibility, and getting into the lungs, they accumulate on the surface of tissues and make breathing difficult; a serious excess of the norm of the content of such particles in the air increases the risk of many diseases of the cardiovascular system, lung and respiratory tract, and cancer in those who often inhale polluted air.

The scientists collected data on the health status of 29,000 babies born in Ohio from 2006 to 2010, and compared them with data on the PM2 fine particle content. 5 in the air in Ohio for the same period. It turned out that children with congenital malformations were more often born in women who breathed heavily polluted air in the period immediately before and after conception.

WHO determines the content of PM2. 5 in the air at 25 mcg per cubic meter; There are not many industrial enterprises in Ohio, so the average PM2 pollution index. 5 by state is much lower than this value - only 13. 79 ?g / m3. However, increasing the concentration of PM2. 5 for every 10 mcg / m3 increases the risk of congenital defects in fetal development by 19%.

Scientists also note that a high concentration of PM2.

5, most likely leads to malformations of the lower body in boys, including the inappropriate development of the urogenital system and, in particular, hypospadias.

The researchers note that they took into account only air pollution in the places of residence of pregnant women, but not at their places of work or on the way from home to work, where many future mothers spend a significant part of the time. Scientists recommend that women planning pregnancy should take measures to breathe as clean air as possible before and after conception.

The study is published in The Journal of Pediatrics.