June, 2013
Abstract
According to a preliminary report on mercury inventory, published in 2000, the point
sources of mercury releases and emissions in Pakistan are a chlor-alkali plant,
light products manufacturing units, dental clinics, incinerators and other coal
based primary or secondary unit operations. Based on this reported preliminary
data, the estimated maximum and minimum emission and transfer of mercury in the
country is about 36,900 and 10,800 kg per year, respectively. At present, there
is no mercury specific legislation in the country. However, development of a
mercury management national action plan is in the making.
In
the present study, mercury levels in and around mercury releasing sources and
in open air are being examined, to identify “Mercury Hot Spots” in
some cities of Pakistan, namely Peshawar, Rawalpindi-Islamabad and Lahore. The
selected sites for measuring air mercury levels were chlor-alkali plant (1),
light products manufacturing companies (2), dental clinics, teaching hospital
and dental colleges (36). The selected sampling points at these sites were
treatment sections, adjacent corridors and open air.
The
high precision RA-915+ mercury analyzer was used to measure mercury levels in
air at the selected sites. Few climatic parameters, like temperature, humidity
and wind speed were measured with Kestrel® 4500 and wind direction with the
help of a Field Compass, whereas geographical coordinates were taken with
Garmin-eTrexGPS. Two separate questionnaires, one each for the dental and
industrial sites, were developed for collecting the background relevant
information regarding mercury use, waste and disposal at each sampling site.
For discussion of the results, ASTDR MRL, 200 ng/m3, US EPA (RfC) 300 ng/m3and
WHO/ACGIH, 25,000 ng/m3 have been referred
Among
all the visited/monitored dental sites in Lahore, Peshawar, Rawalpindi &
Islamabad, eleven (11) sites were observed to be most contaminated, at the time
of the visit. Among dental sites mercury contamination of air was found to be
generally in the increasing order operative section > corridor > open air
and teaching hospitals/dental colleges > general hospitals > private
clinics. Monitoring data indicated high mercury levels, of air in and around
the surroundings of the visited industrial units. The study also showed, the
unawareness to the mercury handling, mishandling of the mercury/mercury
amalgam, mercury containing waste, improper and inadequate ventilation system
and lack of awareness regarding health hazards of mercury, being the main
reasons for the observed elevated levels of mercury in air at some of the visited
sites.
The
data/results, findings and recommendations for releases/emissions control and
phasing out of mercury use in the country is planned to be shared with all
stakeholders, including policy makers and government officials, for appropriate
policy interventions and an action plan to safeguard public health, specially
of children and for the protection of the environment.
Details
of the above investigations, results achieved and recommendations made are
described and discussed in this report.