Air pollution may be damaging men's ability to perform in the bedroom, scientists warn.
New research suggests regular exposure to toxic car fumes is linked with higher rates of erectile dysfunction.
Scientists believe inhaling poisonous particles may be triggering inflammation in blood vessels and starving the genitals of oxygen – affecting men's ability to become sexually aroused.
It follows animal tests that showed regularly breathing in exhaust fumes damages sex drive.
The study, published in the Journal of Sexual Medicine, coincides with renewed warnings from Public Health England that polluted city air is killing nearly 40,000 people a year.
Last week, it released a major report calling for local and national government action to clean up air quality.
It says smog in Britain's cities is causing more cases of heart disease, stroke and lung cancer.
A separate report last week in the European Heart Journal warned air pollution could be causing twice the number of deaths – more than 800,000 a year – across Europe than previously estimated.
Now the latest research suggests men's love lives are also being harmed.
Previous studies have hinted at such a link.
A 2017 US investigation involving more than 400 men found those exposed to the highest air pollution levels were around 15 per cent more at risk of being a flop in the bedroom.
For the latest study, scientists at Guangzhou Medical University in China wanted to see if car fumes affected sexual response.
They exposed rats to regular doses of petrol and diesel exhaust gases and monitored their levels of sexual arousal.
The results showed the longer they were exposed, the less likely they were to respond to sexual stimuli.
-Dailymail