Polycyclic Aromatic Hydrocarbons may increase the risk of Rheumatoid Arthritis

According to research that was published in a British medical journal, those who are exposed to the most Polycyclic Aromatic Hydrocarbons (PAH) substances in their environment-smokers or nonsmokers are more likely to develop rheumatoid arthritis (RA).

Dr. Beidelschies and his team conducted a cross-sectional analysis of the US National Health and Nutrition Examination Survey to ascertain whether there may be a connection between certain environmental toxins and rheumatoid arthritis. In this study, blood and urine samples of  21,987 adults were analyzed. In spite of smoking status, PAHs were reported to be linked to RA prevalence and mediate the bulk of smoking’s impacts on the disease. 

Although patients with the highest quartile of each individual PAH showed an elevated incidence of RA, only 1-hydroxy naphthalene continued to be related in a fully adjusted model (p=0.020). There was an association between PAH body load and RA (p=0.028). Interestingly, smoking was not linked to RA after controlling for PAH body load (p=0.13). According to a mediation study, smoking’s overall impact on RA was 90% accounting for PAH body load. Fully adjusted models did not link phthalates and plasticizers and volatile organic compounds to RA. By adjusting factors such as physical activity, dietary fibre intake, smoking, household income, educational attainment, age, sex, and body weight that might otherwise affect the risk of developing RA, the researchers in this study attempted to establish a relationship between the various levels of toxicants and the incidence of rheumatoid arthritis.

Regardless of smoking habits, experts concluded that environmental PAH is related to the occurrence of RA in the US. Given the combination of environmental toxins like PAHs and heavy metals, as well as the link between socioeconomic position, PAHs, and RA, more investigation is necessary to comprehend the mechanism behind the aetiology of rheumatoid arthritis.


  1. Beidelschies M, Lopez R, Pizzorno J, Le P, Rothberg M B, Husni M E, D’Adamo C. Polycyclic aromatic hydrocarbons and risk of rheumatoid arthritis: a cross-sectional analysis of the National Health and Nutrition Examination Survey, 2007–2016.BMJ Open.2023 May 9;13(5):e071514.