Study Examines White Blood Cell Response to Different Air Environments

Impact of Air Pollution on Health

A study published in *Pediatric Allergy and Immunology* investigated how white blood cells react to air from various environments to gain insights into allergic diseases. With urbanization increasing, exposure to pollutants has risen, contributing to cardiovascular diseases and allergic conditions such as asthma. Interestingly, individuals raised in rural settings exhibit lower rates of asthma and allergies. Despite this, air pollution remains the most significant environmental risk globally, affecting 92% of the population.

Low Allergic Disease Rates in Rural Populations

The lower prevalence of allergic diseases in those from rural areas suggests that distinct environments may trigger different immune responses. The aforementioned study analyzed how these varying environments influence the immune system. The research involved 18 children aged four from Finland, comprising 11 boys, six of whom were predisposed to allergies. Notably, none grew up in rural settings or areas with high air pollution.

Methodology of the Study

Researchers examined the expression of peripheral blood mononuclear cells, which include monocytes, lymphocytes, and macrophages, in reaction to different airborne particles. Following the collection of blood samples, the mononuclear cells were exposed to either farm dust or urban particulate matter.

Findings on Immune Responses

Exposure to farm dust led to an increase in cytokine expression and CD80 receptors, which play a role in immune responses, while decreasing ILT4 receptor expression that typically inhibits immune reactions. In contrast, urban particulate matter resulted in lower expression of both CD80 and ILT4 receptors. Notably, farm dust lacked illness-inducing Polycyclic Aromatic Hydrocarbon compounds.

Implications of Urban Air Pollution

The reduced immune response associated with urban particulate matter contradicts previous studies conducted on mice that suggested an enhanced immune response. Although the precise mechanisms remain unclear, this dampening of the immune response may indicate the body’s attempt to tolerate urban pollutants, disrupting normal immune regulation and increasing susceptibility to allergic diseases.

Future Research Directions

To further investigate the connection between urban particulate matter, rural air quality, and allergic diseases, future research should involve a larger sample size of children and collect air samples from various urban and rural locations.

Author and Reference

Written by Monica Naatey-Ahumah, BSc
Reference: Martikainen, M.V., Rönkkö, T.J., Schaub, B., Täubel, M., Gu, C., Wong, G.,…Roponen, M. (2018). Integrating farm and air pollution studies in search for immunoregulatory mechanisms operating in protective and high-risk environments. *Pediatric Allergy and Immunology*, 29, 815-822. https://doi.org/10.1111/pai.12975