Risk Factors of Asthma Associated a Mining and Phosphate Processing Factory Complex in Southern Tunisia: Cross Sectional and Computational Modeling Study

Abstract

Introduction: Asthma is a common chronic health problem, which is etiologically complex with various risk factors.

Objectives: This study describes the epidemiology of asthma and its loco-regional variability in the southern-west of Tunisia. 3563 people, aged over 14 years, from 9 villages settled around Gafsa city (South-West Tunisia) fulfilled an adapted questionnaire, by direct interview.

Methods: All responders are resident for 10 years or more at the studied locations. The questionnaire concerned their socio-demographic status and asthma related signs such as the presence of physician-diagnosed asthma, wheeze, cough, phlegm, respiratory crisis, etc.). Statistical analyses were carried out using two dimensional contingency tables and Chi square tests.  

Results: 26.89% of the general population is affected by asthma. The disease incidence was significantly associated to subjects’ location. The highest prevalence was observed in R4 (47.48%) and R3 (36.86%) where the lowest values exist in Madjel and Tozeur. Wheeze and its severe forms occurred much frequently in these two regions when compared to others (p< 0.001).  Furthermore, subjects living in couple and educated for less than 12 years were at higher risk to develop asthma. There was no significant correlation between regional distribution of the disease and the other considered risks of factors. These results were confirmed by the docking study regarding the binding and the interactions of sulfur dioxide (SD) and phosphate (PH) with Tumor Necrosis Factor (TNF-α) and Signal Transducer And Activator Of Transcription 6 (STAT6) proteins.  

Conclusions: In conclusion, loco-regional disparities might be consequent to environmental conditions (e.g, dusts, SD and PH liberated from mining and PH treatment), which might enhance the hereditary predisposal to the asthma. The molecular interactions of SD and PH with TNF-α and STAT6 proteins supported the epidemiological findings.