Tiny air pollution particles - like the very ones in bushfire smoke swathing NSW - are doing more than aggravating the lungs of asthmatics. Even short term exposure to the particulate PM2.5 is sending people to hospital for a multitude of newly identified reasons including sepsis and urinary tract infections.

Every 0.001 part-per-million of PM2.5 in the air is linked to 2050 extra hospital admissions, 12,216 days in hospital and almost $46 million in healthcare costs for conditions including lung diseases, diabetes, Parkinson's disease and diabetes, a US study published on Thursday in the BMJ found.

Sydney's smoke pollution has been running at record levels, the government said. Credit:Steven Siewert

PM2.5 was also linked to rises in hospitalisations for illnesses not previously associated with the particulate, such as septicaemia, kidney failure, UTIs and skin and subcutaneous tissue infections.

These newly identified PM2.5-linked diseases accounted for roughly one-third of all hospitalisations associated with the particulate (31 to 38 per cent), suggesting we may be considerably underestimating its health burden, an accompanying editorial warned.