London: Living in a city can take a toll on your health - it can make you obese, infertile, depressed, and may give you potentially life-threatening diseases such as cancer, say researchers.
A number of studies have shown that babies born in cities, and children who grow up in them, face a battery of health problems that afflict both their physical and mental well-being.
In fact, urban living carries a significantly increased risk of chronic health disorders, like mental illness, immune diseases, arthritis, heart disease, cancer and fertility problems, say the researchers.
The studies indicate that daily exposure to urban pollution can affect people before they are even born -- leaving them prone to a lifetime of ill-health.
The researchers have discovered that babies born in cities are bigger and heavier -- normally a good sign -- than those born in the countryside.
But when they compared the placentas of mothers from a busy city and a rural area, they found that the city mums had far higher levels of chemical pollutants called xenoestrogens in their blood -- and in that of their unborn babies.
Xenoestrogens are industrial chemicals that affect human bodies in similar ways to the female hormone, oestrogen. They are found in countless manmade pollutants like petrol fumes, and are abundant in industrial areas than the countryside.
As well as causing excess foetal growth, they have been linked to problems such as obesity, hyperactivity, early puberty, fertility problems and cancers of the lung, breast and prostate, the `Daily Mail` reported.
The researchers, from the University of Granada, Spain, found that although city mothers were older and weighed less than rural mothers, they still gave birth to larger babies.
Dr Maria Marcos, who led the study, has said that the toxic xenoestrogens seem to have a significant effect on the development of unborn children. Her report provides the latest evidence that city air can seriously hinder normal childhood development.
But it doesn`t end there.
Laboratory tests undertaken at the Ohio State University showed how urban pollutants may cause metabolic changes in toddlers resulting in raised blood sugar levels and increased resistance to insulin -- which regulates the way our bodies metabolise carbohydrates.
Dr Qinghua Sun of the university has observed that these pollutants can lead to the development of Type 2 diabetes.
"These fine chemical particles directly cause inflammation and changes in fat cells, both of which increase the risk of Type 2 diabetes. In cities, it would be very difficult to escape the pervasive influence of dirty air that begins early in life," he said.
Another research at Australia`s Centre of Excellence in Vision
Science believes that lack of sunlight is the culprit. It says that exposure to sunshine causes the retina to release dopamine, a hormone that inhibits the excessive eyeball growth that causes myopia.