Dyslipidemia is a critical factor in the development of atherosclerosis and consequent cardiovascular disease. Numerous pieces of evidence demonstrate the association between air pollution and abnormal blood lipids. Although the results of epidemiological studies on the link between air pollution and blood lipids are unsettled due to different research methods and conditions, most of them corroborate the harmful effects of air pollution on blood lipids. Mechanism studies have revealed that air pollution may affect blood lipids via oxidative stress, inflammation, insulin resistance, mitochondrial dysfunction, and hypothalamic hormone and epigenetic changes. Moreover, there is a risk of metabolic diseases associated with air pollution, including fatty liver disease, diabetes mellitus, and obesity, which are often accompanied by dyslipidemia. Therefore, it is biologically plausible that air pollution affects blood lipids. The overall evidence supports that air pollution has a deleterious effect on blood lipid health. However, further research into susceptibility, indoor air pollution, and gaseous pollutants is required, and the issue of assessing the effects of mixtures of air pollutants remains an obstacle for the future.

Background: Psoriasis is a chronic and recurrent inflammatory skin disease. Previous studies have shown that bilirubin has anti‐inflammation and antioxidant effects. However, the various roles of bilirubin in psoriasis patients are still unclear.Objective: To investigate the serum total bilirubin (TB) level in the individuals with psoriasis vulgaris and further evaluate the relationship between serum TB concentration and C‐reactive protein (CRP) to clarify the effect of bilirubin on inflammation.Methods: A total of 214 patients with psoriasis vulgaris and 165 age‐ and gender‐matched healthy control subjects were recruited. The peripheral leukocyte count (white blood cell, WBC) and differential, serum biochemical and immunologic indexes including serum TB, immunoglobulin (Ig) G, IgA, IgM, complement C₃ and C₄, as well as serum CRP concentrations were measured.Results: Results showed that the serum TB level decreased significantly and peripheral WBC, neutrophil, and serum CRP concentrations increased significantly in patients with psoriasis vulgaris. Meanwhile, the serum CRP was negatively correlated with serum TB levels but positively correlated with peripheral WBC and the Psoriasis Area and Severity Index (PASI). Logistic regression analysis showed that the serum TB was a protective factor for psoriasis vulgaris.Conclusion: The present study suggests that lower serum TB is associated with the enhancement of the inflammatory response in psoriasis vulgaris. Therefore, lower serum TB has a prognostic significance for worsening psoriasis vulgaris. Bilirubin may play a crucial role in inflammation by contributing to the inhibition of the inflammatory response.