5 March 2026
by Professor Abdullah Mamun, Dr Edmund Kanmiki and Dr Md. Mehedi Hasan from the University of Queensland’s Poche Centre for Indigenous Health and the ARC Centre of Excellence for Children and Families over the Life Course
The THM Research Project investigated trihalomethane (THM) exceedances in Queensland drinking water and explored whether these exceedances were linked to adverse birth outcomes. Across 27 local government areas, the researchers found that THM exceedances still occur each year, with the highest levels found in regional, remote and socioeconomically disadvantaged communities. Exceedances were most common in the reticulation network, not at treatment plants, and were strongly influenced by season (highest in summer) and temperature.
Interviews with water service providers highlighted operational challenges including ageing infrastructure, high water age, climate impacts, limited staffing, and resource constraints—especially in northern Queensland. Providers identified opportunities to improve THM management through better network optimisation, aeration, filtration upgrades, more frequent sampling, and stronger collaboration across the sector.
The third component of the research linked water quality data with over 135,000 Queensland birth records. While low birthweight was found to be increasing over time—particularly in disadvantaged and remote areas—the study did not find a statistically significant association between THM exposure and adverse birth outcomes after adjusting for key confounders. The researchers recommend improved monitoring, targeted interventions in high risk communities, infrastructure upgrades, and more precise future studies using household level exposure data.