Pakistan Times, The Express Tribune
Published Date: Jun 7, 2013
Indoor mercury levels: Dental clinics, teaching hospitals found surpassing permissible limits
Indoor levels of mercury in 11 dental clinics
and dental teaching hospitals in four cities across the country are beyond the
international permissible limits, according to a study launched on Wednesday.
Exposure to mercury through breathing in
contaminated air or through ingestion can lead to mercury poisoning.
The higher levels of mercury pose health
risks to the medical staff and patients at these dental sites, said researchers
conducted the study at the Sustainable Development Policy Institute (SDPI).
SDPI researchers monitored mercury levels in
air at a total 36 dental sites in Rawalpindi, Islamabad, Peshawar and Lahore.
The study revealed that 11 sites were "most
contaminated" with the levels of mercury beyond the 300 nanograms per cubic
metre prescribed by the United States Environmental Protection Agency.
Five of these dental sites are in Rawalpindi
and Islamabad. One general hospital in Rawalpindi and Islamabad each was also
found to have mercury air levels beyond the prescribed limit.
Mahmood Khawaja, a senior adviser at the
SDPI, said, "Some of the dental students were handling mercury very carelessly.
They were adding mercury to the amalgam as if they were adding sugar to a tea
One of the researchers Maryam Abbasi said, "They (staff and students) do not switch on exhaust fans, they do not open
windows and they do not follow standard operating procedures for mixing Mercury
Khawaja said waste reduction and better
cross-ventilation could reduce the elevated levels by 50 per cent.
Capsulated mercury amalgam which does not
involve manually preparing fillings can further decrease levels by 80 per cent,
The current study relied on a spot
measurement technique and the SDPI will try to conduct detailed exposure
studies of the dental sites to show a daily trend of variations in mercury
levels, he added.
The study also calls for mercury-specific
legislation, indoor air quality standards and ratification of the Minamata
Convention on Mercury.
The research aimed to identify mercury "hot
spots" in the four cities.
The SDPI has not released the names of the
sites due to a confidentiality agreement, however, suggestions have been passed
to the institutions.
Mercury is also found in amalgam dental
fillings, thermometers and fluorescent lamps.
Coal-burning power plants are a major source
of mercury emissions in the air.