A Preliminary Study On Chronic Adverse Health Effects Of Dust Pollution On Human Respiratory System

Dust weather event is a kind of disastrous weather that is common in arid, semi-arid or desert areas. Dust weather event is a floating dust source, which leads severe particle matters (PM) pollution to related regions. In recent years, many epidemiology researches have found that dust pollution caused mainly respiratory system injure. People, who have lived in desertification areas for a long time, might be attacked by desert lung. However, these studies focused primarily on the acute adverse health effects of dust on human. While researchers did not pay enough attention to the chronic adverse health effects of dust. For desert lung, the current studies were limited to the report of incidence of the disease. The clinic character of desert lung has not been summarized systematically, which may lead to misdiagnose or missed diagnosis. Minqin County, Gansu Province is one of the most serious desertification regions in China. While, Pingliang City, Gansu Province belongs to warm and semi-moist agricultural area and influences rarely by dust events. Therefore, Minqin and Pingliang were selected as dust pollution area and control region, respectively. Through comparing analyze to the incidence of respiratory system diseases and symptoms, the status of lung function and the results of chest X-ray between the dust pollution group and the control group, we revealed preliminarily the chronic adverse health effects of dust on human and the clinical characteristics of desert lung. The results will promote the forming of health care ideas and benefit the health of whole population who lived in desertification regions. The main study results as follows: 1.The results revealed that the incidences of chronic rhinitis, chronic bronchitis, chronic cough and chronic sputum were increased of9.6%,8.5%,11.9%and11.2%among non-smokers in Minqin in comparison with Pingliang, respectively; and the differences were significant. Therefore, we concluded that the increasing incidence of some respiratory system diseases and symptoms might relate to long-term dust exposure. It was also displayed that dust pollution had adverse effects on different age people, and those people aged40-59years maybe the major victims. The results also showed that the incidence of the above four diseases and symptoms were ascendant in both males and females in Minqin compared with those of Pingliang, and the differences were significant. However, there were no significant gender different for the incidence in Minqin. In addition, we found that an younger age at onset of chronic bronchitis has been observed in Minqin.2. In comparison with Pingliang, the values of FEV1%and FEV1/FVC%were significant decreased of4.3%and6.6%for non-smokers in Minqin, and the incidence of abnormal lung function was increased of9.5%(p<0.05), respectively. Therefore, we concluded that the decreased lung function might relate to dust pollution. The results also showed that the incidence of mild lung dysfunction was20.1%in Minqin, and it was higher than that of medium or severe pulmonary function injure. The incidence of obstructive pulmonary dysfunction was18.8%, which was the highest ratio among the three types of abnormal lung function. For three different age groups in Minqin, they suffered mainly mild damage of lung function and obstructive pulmonary dysfunction. However, the older the people, the higher incidence of medium injure of lung function and combined pulmonary dysfunction. The results also revealed that the higher incidence of mild injure of lung function and obstructive pulmonary dysfunction were observed both in males and females in Minqin in comparison with Pingliang (p<0.05). However, there was no significant gender different for the incidence of pulmonary dysfunction in Minqin.3. For non-smokers, compared with Pingliang, the incidence of abnormal Chest X-rays were apparent increased of40.5%in Minqin (p<0.05); and the abnormal result of Chest X-rays mainly showed as lung markings. A positive correlation were found between age and incidence of abnormal Chest X-rays in Minqin, which reflected the cumulative injury effects of dust. The results also showed that the higher incidence of abnormal Chest X-rays were observed both in males and females in Minqin in comparison with Pingliang (p<0.05). However, the incidence was increased of17.1%among males in Minqin compared with the females, and the difference was significant.4. Desert lung was the serve outcome of the chronic adverse health effects of dust. The results showed that the prevalence of desert lung was1.7%in Minqin, and there was no significant gender different for the prevalence. The ratio of pneumoconiosis I was85.7%(6/7). All patients were beyond50years. The relation was not been observed between smoking and desert lung. The results of chest X-ray showed that circular small opacities spread all the bilateral lung fields, and the ratio of opacity q was71.4%. The results also displayed that the major clinic symptoms of desert lung were chronic cough and chronic sputum, and it was possible for these patient complicated with some respiratory system diseases such as chronic bronchitis and tuberculosis. We also found that the incidence of lung dysfunction was over40percent in7desert lung patients, whose lung injure belonged to mild or medium damage, and showed obstructive or combined pulmonary dysfunction.