Environmental pollution and systemic sclerosis manifestations: a pilot study on benzene and particulate exposure

Many works have studied interactions between genetic and autoimmunity but only a few have studied the interactions between autoimmune diseases, such as systemic sclerosis (SSc), and exposure to environmental pollutants, reporting no conclusive. Results This study aims to analyze the relationships between outdoor concentration of benzene (B) and particulate matter 10 m (PM10) with clinical manifestations of SSc in a big Italian city. A pilot cohort study of 88 SSc patients filled a validate selfadministered questionnaire to investigate potential risk exposure before and after the onset of the disease. The demographic and clinical characteristics were recorded. The average mean concentrations of B (11 monitoring sites) and environmental PM10 (14 sites) were computed using data from monitors located throughout the Lazio region, in Italy, and they were correlated with demographic and clinical characteristics. Besides maps of the particle’s diffusion have been developed through spatial data modelling techniques (FAI-K geostatistical analysis). The questionnaire validation has resulted in an agreement of the overall experts about of 94%, with a very good concordance (Inter-observer agreement K Cohen test = 0.8019; p < 0.01). SSc patients with diffuse skin disease were exposed 2 years before the onset of Raynaud’s phenomenon to higher concentrations of benzene (8.5 1.5 mg/m3) in respect to patients with limited skin disease (4.97 2.7 mg/m3) [p=0.02]. The maps of the particle’s diffusion expected values, obtained through FAI-K geostatistical analysis, show higher concentration of PM10 and B in the residence area of patients with diffuse skin disease (Indicative Goodness of Fit = 0.0667; K-order Rank = 1; Jacknife = 1.0016). This pilot study suggests a possible role of benzene in the developing a diffuse skin disease. Moreover geostatistical maps are of great importance because they allow to estimate PM10 and B concentration all over monitoring area and not only where the samples are performed, other than showing clearly the pollutants distribution in the environment.