Abstract

In Bangladesh, air-pollution, particularly in urban areas, have reached an alarming level, the poor and the have-nots are the most vulnerable. Dhaka city has been described as having the highest level of ambient air pollution (concentration of Pb in air is 463 ng/cu m). In the roads there is high concentration of exhaust pollutants both from diesel (SOX, NOX) and petrol/octane (lead) vehicles. Other concerned pollutant of the city air are particulate matter (either total suspended particulate i.e. TSS or respirable of less than 10 microns in diameter (PM-I0) and ozone formed as a result of atmospheric reactions between HC and NOX in presence of sunlight. In a survey of 777 primary school children 4-7 years old in Dhaka, CDC, Atlanta scientists found blood lead level higher than permissible CDC level (>10 microgram/dl) (Blood lead levels of primary school children in Dhaka, Bangladesh by Reinhard Kaiser et al, Environmental Health Perspectives, volume 109.6, June 2001).

In 1999 government decided to get rid of lead from fuel (Daily Star, 24 January 1999). Atomic energy commission (AEC) claimed that lead concentration in Dhaka air had decreased but stills concern about lead poisoning remains as environmental lead stays for decades. As the vehicles are not equipped with catalytic converters/diesel filters, VOC/ SVOC's have remarkably increased in air. Emissions from 2 stroke auto-rickshaws in Dhaka were found to contain 4-7 times the maximum permissible levels of VOC's (M. Alauddin. Daily Star, September 20 1999). Emissions from small industries in residential areas and construction of high rise buildings are implicated with air pollution. Smokes from the brick-kilns in the suburb also add pollutants to air. Other concerned pollutant of the city air is particulate matter, either total suspended particulate (TSS) or respirable particulate of less than 10 microns in diameter (PM-I0) and ozone formed as a result of atmospheric reactions between HC and NOX in presence of sunlight.

Children's breathing rate is more than adults -as a result they absorb more pollutants, and retain them in the body for longer period, their blood-brain-barriers are not well developed, and immune systems are immature and therefore they are more vulnerable to intoxication. Air pollution causes both short term and long term effects on children e.g. breathing difficulty, immuno-suppression, allergy and/or asthma /wheezy bronchitis, pneumonia, brochiolytis, (intrauterine growth retardation) IUGR, (low birth weight) LBW, pre-term delivery, developmental anomaly and delay, acute and chronic neurological effect, learning difficulty, school failure, headache/fatigue, kidney disorders, anaemia, cancers, skin, eye, ear, nose and throat (ENT) problems. Air pollution interferes with the development and growth of a child and in women at reproductive age indirectly affects foetal growth and development.

Dhaka Shishu (Children) Hospital (DSH) has a large outpatient department (OPD) where approximately 500 children (particularly low income group) with acute and chronic problems are seen everyday. It has been seen that children with respiratory problems particularly "wheezy chest" and acute respiratory infection (ARI) and also childhood malignancies have increased over time. Shishu Bikash Kendro"(SBK) or "Child Development Centre" at DSH is a centre for assessment and management of children ranging from mild to moderate disability as well as for helping normal children and their parents to manage minor to major behavioural problems; main objective of SBK is to improve quality of lives of children of Bangladesh. SBK has been encountering a number of children with developmental delay and acute neurological problems showing high lead content in their blood. Air pollution can be considered as a serious preventable cause of child health problems.

The purpose of this paper is to review the prevalent air quality of Dhaka City, their effects on children's health and also those of women of reproductive age, so that effective and immediate measures can be taken for prevention.