Indoor Dust Increases the Risk of Iron-Loading Anemia in Mice through Exogenous Iron-Induced Ineffective Erythropoiesis

Humans spend most of their time indoors, coming into contact with various pollutants through indoor dust. Emerging epidemiological evidence suggests that indoor dust is a potential influencing factor for hematologic disorders, especially anemia. However, the causal relationship between indoor dust and the occurrence of anemia, as well as the underlying mechanisms and the role of its components, remains unclear. In this study, we collected indoor dust samples from an industrial city in northern China to set up a mouse inhalation model at environment-related concentrations and found that the dust exposure increased the risk of anemia by disrupting hematopoietic stem cell differentiation and erythrocyte maturation in the bone marrow (BM), leading to a decreased number of mature erythrocytes in the peripheral blood. Mechanistically, we clarified that these BM hematopoietic disorders arose from iron metabolism disorders, including iron overload and diminished levels of divalent metal transporter 1, transferrin receptor, and ferroportin in the lungs and BM. Furthermore, using stable isotope tracing, we identified that the elevated levels of iron in the lungs partially originated from abiogenic natural particulate matter, indicating that iron in indoor dust could enter the body, leading to iron overload and an increased risk of anemia. These findings provide evidence for understanding the potential risk of anemia induced by exposure to iron-containing indoor dust.