While studies have proven and raised alarms about the connection between air pollution and health risks such as respiratory diseases, various forms of cancer, and stroke, among others, not much is known about its impact on bone health. However, a study conducted in India has found a link between bone health and air pollution.
The handful of studies conducted in the past to establish this connection have remained largely inconclusive, and this study led by the Barcelona Institute for Global Health (ISGlobal), has managed to find a conclusive link. "This study contributes to the limited and inconclusive literature on air pollution and bone health," said Otavio T. Ranzani, first author of the study, in a statement.
A locally-developed model used for the study
The study examined the connection between bone health and air pollution in 28 villages outside Hyderabad, in the south Indian state of Telangana. Over 3,700 people were evaluated for the purpose of the study. A locally-developed model was employed to gauge outdoor exposure at residence to air pollution. This was in terms of exposure to black carbon and fine particulate matter, which are solid particles of a diameter of 2.5 μm or lesser. Data for the type of cooking fuel used was collected through a questionnaire.
Next, the researchers measured the bone density of the participants using a form of radiography known as dual-energy x-ray absorptiometry. The bone mass of the left hip and at the lumbar spine was also measured. Using the fuel data and bone mass data, the authors tried to find a link between pollution and bone health.
A link between air pollution and bone health exists
A concerning discovery— that low levels of bone mass were associated with ambient air pollution—especially fine particles—was made. However, a correlation between bone health and biomass as fuel was not found.
Explaining the mechanism that led to the loss of bone mass, Ranzani said, "Inhalation of polluting particles could lead to bone mass loss through the oxidative stress and inflammation caused by air pollution". This could serve as one of the explanations for the progression of Osteoporosis, a disease where the quality and density of the bone reduces gradually—among certain populations—especially aging ones.
What they also found was that the average annual exposure to particles known as PM2.5 was 32.8 μg/m3. This was alarming as the safe level recommended by the World Health Organisation(WHO) was only 10 μg/m3.
Talking about the study's contribution to the increasing research in the area, Cathryn Tonne, coordinator of the study, said,"Our findings add to a growing body of evidence that indicates that particulate air pollution is relevant for bone health across a wide range of air pollution levels, including levels found in high income and low-and medium income countries."