Indoor particulate matter in Sri Lankan industries: a comparative assessment against local and global air quality standards

Abstract

Indoor air quality (IAQ) in industrial environments is a critical determinant of occupational health; however, it remains an under-regulated domain in Sri Lanka. Prolonged exposure to elevated particulate matter (PM₁₀) levels in enclosed workplaces is linked to respiratory diseases, cardiovascular complications, and reduced worker productivity. This study presents a longitudinal assessment of PM₁₀ concentrations across 15 industrial sites spanning seven key sectors, including textile and apparel, rubber and plastics, food and beverage, electronics, cement production, logistics, and power generation, based on data collected from 2015 to 2024. Over 300 data points were analyzed from more than 80 unique indoor locations, covering both general workspaces and high-exposure zones such as boiler rooms, dye houses, and chemical stores. Measurements were conducted using USEPA-approved high volume air samplers in accordance with the Sri Lankan Ambient Air Quality Standard for PM₁₀. The results revealed that several zones, particularly in fabric processing, electronic assembly, and tea packaging, recorded PM₁₀ concentrations that significantly exceeded the national and WHO guidelines. In some areas, levels exceeded 150 µg/m³, posing chronic health risks to workers through inhalation of respirable particulates. This study highlights the urgent need for regulatory IAQ frame works tailored to the industrial landscape of Sri Lanka. This study provides critical evidence to support policy reform, implementation of engineering controls, and workplace health interventions, contributing to sustainable and safe industrial development aligned with international occupational health standards.