ENVIRONMENTAL POLLUTION AND SYSTEMIC SCLEROSIS: A PILOT STUDY ON BENZENE AND PARTICULATE EXPOSURE AS RISK FACTORS FOR THE SYSTEMIC MANIFESTATIONS

Background: The association of systemic sclerosis (SSc) with the exposureto environmental agents is supported by a number of case reports and somecase-control studies. No conclusive results have been reported, but there aresome evidences that exposure to vinyl-chloride-polymers (PVC), silica dustor organic solvents such as benzene (B) and xylene (X) may be implicated.Furthermore a higher prevalence of scleroderma in boroughs in close proximityto a major airport, has been reported, but few data on air pollution exposure andrisk of systemic sclerosis are available. Recently, particulate air pollution hasbeen consistently linked to increased risk of arterial cardiovascular disease.Objectives: We studied relationships between outdoor concentration of B andparticulate with clinical manifestations of SSc based, for the exposure, on theurban residence of patients.Methods: Before patient administration, the questionnaire was validated byDelphi technique (4 rheumatologists, 4 statisticians and 2 common people).A cohort study of 88 SSc patients, filled the validated self administeredquestionnaire (analyzing drug, work and environmental exposure) toinvestigate potential risk exposure before and after the onset of the disease.The average mean concentrations of B (11 monitoring sites) and environmentalparticulate matter with aerodynamic diameter ≤ 10 μm(PM10) (14 sites) werecomputed using data from monitors located throughout the Lazio region, inItaly. In a sample of 33 patients we performed correlations between the concentrationsof PM10 and B with the demographic and clinical characteristics,going back to a prior exposure of 2 years before the onset of Raynaud’s phenomenon(RP).Results: The questionnaire resulted in an agreement of the overall expertsof about 94% (according to11/190 disagreement for comprehension, onlyfew lexical modifications were done to improve the questionnaire afterthe consensus between the experts), with an Inter-observer agreement(measured throughout K Cohen test) of 0.8019(p <0.01) showing a very goodconcordance. The mean disease duration from the RP onset was 13.0±9.4years and the mean age was 55.0±12.9 years. 92.5% of patients were female.No correlations were found between different clinical disease characteristicsand drug assumption and work exposure.Considering patients that lived in Lazio, SSc patients with diffuse skin diseasewere exposed 2 years, before the onset of RP, to a higher concentrationsof benzene (8.5±1.5µg/m3) with respect to patients with limited skin disease(4.97±2.7µg/m3), which was statistically significant of p=0.02. Furthermorethe concentrations of benzene correlated directly with the skin score (R=0.3,p≤0.05) and inversely with DLCO (R=-0.36,p≤0.05). SSc patients with ulcerswere exposed 2 years before the onset of RP to higher concentrations of B(6.4±3.2 µg/m3), than the patients without ulcers (4.9±2.3µg/m3), but the differencedid not reach statistical significance.Conclusions: This study, on the role of environmental agents in themanifestations of SSc, suggests an increased exposure to benzene in thedevelopment of a diffuse skin disease and a possible predisposing effect onthe occurrence of ulcers.Disclosure of Interest: None Declared