Pre-existing pulmonary function abnormality exacerbates the impact of occupational dust exposure on incident hypertension: Evidence from a large occupational cohort

• ODE and PFA independently increase hypertension risk. • Respirable particles (≤10 µm) and inorganic dust are the main risk factors. • Longer dust exposure duration leads to higher hypertension risk. • Combined ODE and PFA synergistically raise hypertension risk. • Mendelian randomization confirms the causal link between ODE, PFA, and hypertension. This study aimed to examine the independent and joint effects of occupational dust exposure (ODE) and pulmonary function abnormalities (PFA) on the incidence of hypertension, and to assess whether pre-existing PFA modifies the ODE–hypertension relationship. A prospective cohort design was used, drawing data from the Guangdong Key Occupational Diseases Surveillance Project (2021–2023), which included 144,627 workers from 21 cities in Guangdong, China. ODE and PFA were assessed using standardized protocols, and hypertension was defined as elevated blood pressure or use of antihypertensive medication. Cox proportional hazards models, restricted cubic splines, and interaction analyses were performed to evaluate associations, and Mendelian randomization (MR) using UK Biobank data was conducted to assess causality. At baseline, 33,766 participants (23.3 %) had PFA, and during follow-up, 14,996 (10.4 %) developed hypertension. Both ODE (HR = 1.12, 95 % CI: 1.08–1.16) and PFA (HR = 1.19, 95 % CI: 1.14–1.23) were independently associated with increased hypertension risk ( P < 0.001), with a higher combined effect (HR = 1.39, 95 % CI: 1.31–1.47). A positive trend was observed between dust exposure duration and hypertension risk (HR = 1.11 for ≥6 years vs. <2 years; P for trend = 0.017). Respirable dust (≤10 μm) and inorganic dust were significantly associated with increased hypertension risk (HR = 1.16 and 1.13). MR analysis supported a causal relationship between ODE, PFA, and hypertension. These findings indicate that pre-existing PFA amplifies the hypertensive effects of ODE, highlighting the importance of respiratory health interventions to reduce hypertension risk among dust-exposed workers.