Effects of fine particulate matter on bone marrow-conserved hematopoietic and mesenchymal stem cells: a systematic review.

The harmful effects of fine particulate matter ≤2.5 µm in size (PM) on human health have received considerable attention. However, while the impact of PM on the respiratory and cardiovascular systems has been well studied, less is known about the effects on stem cells in the bone marrow (BM). With an emphasis on the invasive characteristics of PM, this review examines the current knowledge of the health effects of PM exposure on BM-residing stem cells. Recent studies have shown that PM enters the circulation and then travels to distant organs, including the BM, to induce oxidative stress, systemic inflammation and epigenetic changes, resulting in the reduction of BM-residing stem cell survival and function. Understanding the broader health effects of air pollution thus requires an understanding of the invasive characteristics of PM and its direct influence on stem cells in the BM. As noted in this review, further studies are needed to elucidate the underlying processes by which PM disturbs the BM microenvironment and inhibits stem cell functionality. Strategies to prevent or ameliorate the negative effects of PM exposure on BM-residing stem cells and to maintain the regenerative capacity of those cells must also be investigated. By focusing on the complex relationship between PM and BM-resident stem cells, this review highlights the importance of specific measures directed at safeguarding human health in the face of rising air pollution.