GREATER long-term exposure to air pollution, specifically PM2.5, NO2, and NOx, is associated with an increased risk of developing venous thromboembolism (VTE), according to findings from the Multi-Ethnic Study of Atherosclerosis (MESA).
Air pollution exposure is a growing public health concern, with emerging evidence suggesting links to cardiovascular and thrombotic diseases. This study aimed to explore whether chronic exposure to specific air pollutants is associated with a higher risk of VTE, a potentially life-threatening condition characterised by blood clots forming in the veins. The analysis leveraged data from the MESA cohort, a diverse, community-based sample with detailed pollution metrics and long-term follow-up.
The study analysed data from 6,651 participants aged 45–84 at baseline (53% female) who were recruited between 2000 and 2002. Air pollution exposure was assessed using a validated model incorporating spatio-temporal monitoring, with four key pollutants measured fortnightly: PM2.5, NO2, NOx, and O3. Over a median follow-up of 16.7 years, 248 VTE events were identified. Adjusted hazard ratios (HR) demonstrated significant associations with VTE for higher pollutant levels: per 3.6 µg/m³ increase in PM2.5 (HR 1.39; 95% CI 1.04–1.86), per 13.3 ppb increase in NO2 (HR 2.74; 95% CI 1.57–4.77), and per 30 ppb increase in NOx (HR 2.21; 95% CI 1.42–3.44). O3 was not significantly associated with VTE risk. These results indicate that prolonged exposure to PM2.5, NO2, and NOx may contribute to the development of procoagulant states, increasing susceptibility to blood clots.
This study reinforces the need for clinical awareness of air pollution’s impact on vascular health, particularly for patients at high risk for thrombotic events. Future research should explore interventions to mitigate air pollution exposure and examine underlying mechanisms linking pollutants to VTE. Policymakers and healthcare providers must consider these findings when addressing air quality standards and developing strategies to reduce environmental health risks.
Katrina Thornber, EMJ
Reference
Lutsey PL et al. Air pollution is associated with increased risk of venous thromboembolism: the Multi-Ethnic Study of Atherosclerosis. Blood. 2024; blood.2024026399.
