For many, the only redeeming feature of a hot summer is the mango, popular as the king of all fruits.

But few are aware that most mangoes are being turned a beautiful golden yellow using artificial ripeners that are hazardous to human health.

The ripeners are used despite a government warning against it. There has been no serious effort to stop their use except periodic seizures of the chemical banned as unsafe.

In South India's biggest mango market at Hyderabad, some 1500 tonne of mangoes reach everyday.

By the time the crate of mangoes reaches outside the market, it will be a luscious, delectable yellow. After a close look into what is being packed in along with the mangoes one can find a pouch of calcium carbide, an artificial ripener that turns the fruit colour to yellow.

''We put carbide with all the mangoes. When packed airtight, it will ripen in 3-4 days,'' said a seller.

Toxic substance

Calcium carbide is a toxic substance banned under the Prevention of Food Adulteration Act. It contains traces of arsenic and phosphorous that is hazardous. Once dissolved in water, the carbide produces acetylene gas that quickens the ripening process.

''It is a very well known toxic substance with very well known allergic manifestations. Calcium carbide causes irritation of eyes, itching of mouth, burning sensation in mouth when you eat the mango,'' said Dr Ramesh Kancherla, Medical expert.

Those in the know say it is possible to identify fruits that have been treated with carbide. So be warned before you reach out for that golden fruit.