SHUNNING junk food and choosing health, you may have decided to go natural with fruits, but caution is advised because some traders here have relied on artificial means to produce gleaming fruits that are definitely unhealthy . And, mangoes seem to be the prime target of nefarious traders. The magnitude of the problem came to fore on Monday after the Chennai Municipal Corporation raided the Koyambedu market and seized around 800 kg artificially ripened Banganapalli mangoes. Officials also seized 750 kg calcium carbide used for the procedure. Officials had conducted a raid earlier too and warned traders, but the practice obviously continues. Calcium carbide is known to be extremely hazardous since it contains traces of arsenic and phosphorous. Once dissolved in water, the carbide produces acetylene gas, which may affect neurological system, induce prolonged hypoxia headache, dizziness, mood disturbances, sleepiness, mental confusion, memory loss, cere bral edema and seizures. Health officer Revathy , who led the raid, told Express, "As it takes just 24 hours to ripen mangoes, many use this dangerous chemical. We had cautioned traders against using it and issued notice that raids would be conducted. Fruit market associations were also notified." "On 21 May we seized around 1200 kg calcium carbide and destroyed around 450 kg mangoes. We have decided to conduct surprise raids once in 10 days," she said. Revathy said people should be careful while buying mangoes and look to avoid ones with black spots or appearing too bright or golden. "Even papaya and banana are being artificially ripened," she warned.