A study on brick kiln workers exposed to PAHs published by the researchers this month (August) in Science of Total Environment, shows the employees having abnormally low haemoglobin and red blood cell counts.
Also, the workers had elevated white blood cell counts and superoxide dismutase levels in the blood that are suggestive of inflammation and oxidative stress, says Atif Kamal, an author of the study and scholar at the department of environmental sciences, Quaid-i-Azam University, Islamabad.
Brick making, a widespread industry in Pakistan, India and Bangladesh, is typically manned by workers on low wages and poor health cover. Low-cost fuel like coal, wood, waste oil and even plastic and rubber are used to fire kilns, resulting in the production of PAHs and other toxic pollutants.
In the study, the first on PAH attempted in Pakistan, blood and urine samples were taken from 46 male workers and compared with samples from a group of non-workers.
The results show that regardless of the possibility of brick kiln workers suffering from poor nutrition, their anaemic state and other blood anomalies could be linked to exposure to smoke present in the environment around brick kilns, says Kamal.
“PAHs have many long-term health effects, including their known carcinogenic and mutagenic properties,” says Kamal. He lists oxidative stress, neurological dysfunction, genotoxicity, hepato-toxicity, haematological changes, anaemia, pulmonary disease, lung cancer, bladder cancer and cardiovascular diseases as being among the risks.
Zafar Fatmi, assistant professor and head of the environmental health sciences division at the Aga Khan University in Karachi, comments that the study has methodological limitations arising from differing socio-economic backgrounds between brick kiln workers and the control group.
“Brick kiln workers are a socioeconomically disadvantaged group as can be seen by several parameters in the study. The body mass index and educational status are grossly different between the two groups and this is confounding blood parameters,” Fatmi tells SciDev.Net.
> Link to abstract in Science of Total Environment
This article has been produced by SciDev.Net's South Asia desk.