Air pollution can affect bone density

Deteriorating air quality in Delhi. A file photograph.

LUNG cancer, stroke and respiratory diseases are some of the documented effects of air pollution on health. But there are other morbidities, such as poor bone health, although few studies have been carried out and the results are inconclusive. Now, a study conducted in India led by the Barcelona Institute for Global Health (ISGlobal), an institution supported by the Spanish banking foundation La Caixa, has found an association between exposure to air pollution and poor bone health.

The new study performed by ISGlobal’s CHAI (Cardiovascular Health effects of Air Pollution in Telangana, India) Project, and published in January in “Jama Network Open”, analysed the association between air pollution and bone health in over 3,700 people from 28 villages outside the city of Hyderabad. The authors used a locally developed model to estimate outdoor exposure at one’s residence to fine particulate matter (PM, suspended particles with a diameter of 2.5 micrometres or less) and black carbon. The participants also answered a questionnaire on the type of fuel they use for cooking.

The authors linked this information with bone health assessed by measuring bone mass at the lumbar spine and the left hip. The annual average exposure to ambient PM 2.5 was 32.8 micrograms/m3, far above the maximum levels recommended by the World Health Organisation (10 micrograms/m3). As many as 58 per cent of the participants used biomass fuel for cooking.

The results showed that exposure to ambient air pollution, particularly to fine particles, was associated with lower levels of bone mass. No correlation was found with the use of biomass fuel for cooking.

“This study contributes to the limited and inconclusive literature on air pollution and bone health,” said Otavio T. Ranzani, ISGlobal researcher and first author of the study. Regarding the possible mechanisms underlying this association, he said: “The inhalation of polluting particles could lead to bone mass loss through the oxidative stress and inflammation caused by air pollution.”

Osteoporosis is a disease in which the density and quality of the bone is reduced. Globally, it is responsible for a substantial burden of disease and its prevalence is expected to increase owing to an ageing population.