Critical Review of Lead Pollution in Bangladesh.

Background: Lead (Pb) poses a severe threat to human health and the environment. Worldwide Pb production and consumption have significantly increased along with unplanned industrialization and urbanization, lead smelting, and lead-acid battery processing. The improper management of Pb-containing elements is responsible for Pb pollution. Lead's persistence in nature and bioaccumulation in the food chain can lead to adverse health impacts.

Objectives: The present study aims to describe Pb contaminated sites in Bangladesh and Pb concentration in the atmosphere, water, sediments, soil, vegetables, fish, and other foods in Bangladesh.

Methods: The present study searched a total of 128 peer-reviewed articles based on a predefined set of criteria (keywords, peer-reviewed journals, and indexing in Scopus, Science Direct, Web of Science, Springer, PubMed, Directory of Open Access Journals (DOAJ), and Bangladesh Journals Online (BanglaJOL) and exclusion criteria (predatory journal and absence of full text in English) and finally selected 63 articles (58 research articles and five (5) reports). The relevant findings on Pb exposure, sources, routes, diet, and impacts in Bangladesh were combined and presented.

Results: The reviewed studies identified 175 Pb contaminated sites through soil sample assessment in Bangladesh. The study determined Pb concentrations in air (0.09-376.58 μg/m³, mean 21.31 μg/m³), river water (0.0009-18.7 mg/l, mean 1.07 mg/l), river sediments (4.9-69.75 mg/kg, mean 32.08 mg/kg), fish (0.018-30.8 mg/kg, mean 5.01 mg/kg), soil (7.3-445 mg/kg, mean 90.34 mg/kg), vegetables (0.2-22.09 mg/kg, mean 4.33 mg/kg) and diet items (0.001-413.9 mg/kg, mean 43.22 mg/kg) of which 38.8%, 27.8%, 54.5%, 68.8%, 9.7% and 100% of samples, respectively, exceeded related World Health Organization (WHO), Food and Agriculture Organization (FAO), United States Environmental Protection Agency (USEPA) and Bangladesh Standard Testing Institution (BSTI) guidelines. The present study found that industrial soils are severely polluted with Pb (7.3-445 mg/kg) in Bangladesh. A high Pb concentration has been found in fish muscle and foods, including leafy and non-leafy vegetables collected from different places in Bangladesh.

Conclusions: Lead-contaminated foods can enter the human body through dietary intake and consequently lead to long-term adverse health effects. This study may help policymakers to formulate national policies with effective mitigation plans to combat the adverse health impacts of Pb in Bangladesh.

Competing interests: The authors declare no competing financial interests.