Experts from Duke University, USA undertook a research using rats in a laboratory.
There are several industrial plants and factories in the Chinese capital of Beijing.
Because of this, the air in the city is highly polluted.
So, the research was conducted on the pregnant rats which inhaled this polluted air.
It was established that the rats which inhaled this polluted air suffered from swelling in the tissues of lung & liver and also cause allergy. The fat content in the body rose and the body weight also increased.
As the rats had problems producing insulin, it was found that they had type-2 diabetes as well.
The same tests were done with another set of pregnant rats who inhaled unpolluted air. It was established that these rats did not have any of the complaints mentioned above.
So, warning has been given that inhaling polluted air might lead to increase in body weight.