The Telegraph e-Paper
The Telegraph
Since 1st March, 1999
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Metals in dust, the silent killers

May 10: In every speck of dust that enters your nostrils, there is a deadly combination of heavy metals that is waiting to create havoc in your body.

The dust in the city has alarmingly high concentration of heavy metals.

A survey conducted by a teacher of B. Borooah College has revealed that concentration of some heavy metals like copper, chromium, lead, cadmium, nickel, zinc and cobalt are several times higher than usually found in normal soil.

Bijoy Sankar Goswami, a faculty of chemistry department of B. Borooah College, collected dust samples from 16 places in the city and tested them in a laboratory.

Samples were collected from Jalukbari, Boragaon, Be-ltola Chariali, Lokhra, Kha-napara, Ganeshguri, Bhangagarh, Paltan Bazar, Chandmari, Guwahati Club, Kach-ari, Panbazar, Fancy Bazar, Bharalu, Maligaon and Adabari.

In the survey, it was found that concentration of chromium is as high as 210 mg per kg (mg/kg) at Paltan Bazar, which should be 10 to 50 mg/kg. Fourteen out of the 16 places had higher percentage of chromium than the normal amount. In seven places, it was more than 100 mg/kg.

The presence of zinc concentration is more than normal soil (10 to 15 mg/ kg) in 10 places: Jalukbari (210 mg/kg), Khanapara (70), Chandmari (80), Guwahati Club (70), Kachari (90), Panbazar (400), Fancy Bazar (80), Bharalu (420), Maligaon (60) and Adabari (170). Similarly, presence of concentration of nickel is more than normal soil in nine places — Beltola Chariali, Lokhra, Bhangagarh, Guwahati Club, Kachari, Panbazar, Fancy Bazar, Bharalu, and Maligaon.

Lead is found in higher percentage than in normal soil (0.1 to 20 mg /kg) in Jalukbari (200 mg/kg), Boragaon (77), Beltola Chariali (22), Khanapara (190), Chandmari (180), Guwahati Club (42), Kachari (75), Fancy Bazar (170), Bharalu (91), Maligaon (210) and Adabari (51).

“In the present investigation, it has been observed that the presence of chromium, zinc, manganese and copper in street dust are considerably high in almost all the locations. This also points to the level of dust contaminants,” said the report.

The survey said the traffic police are the primary sufferers of the street dust contamination. A peek into the Central Police Hospital at Panbazar reveals that the city traffic policemen are afflicted by several diseases because of the high amounts of street dust they inhale, the most common of them being chronic bronchitis and asthma.

The survey pointed to the increasing number of vehicles which contributes to dust pollution. “The study showed that street dust was significantly contaminated. Vehicular emission is the principal source of contamination of street dust,” said the report.