Delhi's worst air quality of the season is a matter of serious concern even for the city's healthy residents as it could affect their sex drive and activity, fertility experts said on Sunday.

According to experts, air pollution can cause 30 per cent reduction in sex activity due to its adverse effects. And after Diwali, the national capital city is witnessing the worst air quality in the past 17 years. 

"There are a lot of heavy metals in the air, which directly affect the hormones in the body. In India, 15 per cent of the male population is infertile, a rate greater than that of female," said Sagarika Agarwal, fertility expert associated with city based Indira IVF Hospital.

"Particulate matter carries with it polycyclic aromatic hydrocarbons, lead cadmium and mercury which can possibly affect the hormonal balance and be toxic to sperm," Agarwal said. 

According to Agarwal, reduction in testosterone or oestrogen level may lead to low desire for intercourse, thereby hindering the sex life. But to avoid changes in fertility, one simple solution could be to use multi-layer filter masks while outdoors.

Experts said that Delhi has seen a drastic increase in the level of particulate matter (PM 2.5) which is a fine matter about 30 times finer than human hair. 

They said that November, after Diwali, commenced with a recorded PM 2.5 as beyond scale value of 500 µg/m3 and increased to 600 and 700 µg/m3 in the later days, much higher than the Central Pollution Control Board norms of 250 µg/m3.

Arvind Vaid, a city based IVF expert, said that breathing too much of pollution leads to a higher concentration of free radicals in the blood. That causes a lower sperm quality even in fertile men. 

"The pollution level in Delhi right now is enough to cause infertility in male and increases the chances of miscarriage in woman," said Vaid.

Priyanka Purohit, an gynaecologist associated with Ram Manohar Lohia Hospital, said that air pollution is one of the greatest factors that has an adverse effect on pregnancy.