Lung Function and Respiratory Health of Populations Living Close to Quarry Sites in Palestine: A Cross-Sectional Study

An assessment of the immune status of some stone quarry workers in Ondo state, Nigeria

Stone quarry activities in Nigeria are mostly unregulated such that the workers in these quarries are continuously exposed to the inhalation of silica dust. It has been observed that silica dust particles negatively impact the health of stone quarry workers which usually manifest as respiratory difficulties, asthma-like illnesses and other adventitious events of the lungs. The study was designed to evaluate the probable immunological impact of silica dust inhalation from stone crushing by workers. Blood samples were collected from consenting workers and analyzed for total white blood cells and their subsets. Absolute CD4 cells numbers were also determined. The results indicated that neutrophils and eosinophils numbers increased significantly (P < .05) and CD4 counts declined significantly (P < .001). Alteration in these proportions is a pointer to the injurious impact of silica dust on the immune system of these workers. The findings in this study should spur actions in the education of these workers on the need for the use of proper personal protection equipment and the establishment of a scheme to periodically carry out a health assessment check to identity those at most risk of developing chronic illnesses.

Health risks and perceptions of residents exposed to multiple sources of air pollutions: A cross-sectional study on landfill and stone mining in Danang city, Vietnam

Health risks and perceptions of residents living nearby landfills or stone mines/quarries have been well documented; however, the multiple impacts of these two pollution sources have yet to be investigated. This study aims at giving insights into the impacts of residents exposed to two pollution sources in Danang city, Vietnam: Khanh Son landfill and Phuoc Tuong quarry. In this cross-sectional study, 7-point-Likert scale questionnaires were used to collect information from 314 respondents which were divided into three groups: i) Landfill-Stone mine (LS) exposed group within 1 km from both sources, ii) Stone mine (ST) exposed group within 1 km from the stone mine, and iii) the far-exposed group about 2-3 km from the two emission sites. Air pollutants (including H₂S, CH₄, and total suspended particles (TSP)) and noise levels were also sampled. In addition, we estimated the potential health risk assessment due to the exposure to hydrogen sulphide in the study areas. The findings have shown that 1) There is a statistical difference (p-value < 0.001) between the two exposed groups and far-exposed group regarding health risks and residents' perceptions; 2) Compared to the ST exposed group, the LS exposed group statistically showed a higher perception to bad odours and skin diseases; lower satisfaction with regards to the personal health condition and the operation of the landfill; and higher willingness to change current living locations; and 3) There is evidence to indicate that elevated concentrations of air pollutants are associated with the high self-reported health risks and residents' perceptions. Urgent actions should be focused on the LS exposed group, landfill and quarry operations to prevent further adverse health effects.

Comprehensive Chemical Dust Suppressant Performance Evaluation and Optimization Method

Chemical dust suppression is an effective dust control technology. A dust suppressant component evaluation method that facilitates a complete selection of safe, efficient, and economical chemical materials has not been explored. Considering dust suppression performance, environmental safety, and cost-effectiveness of chemical dust suppressant technology, this study constructs a comprehensive evaluation index system of chemical dust suppressant performance, including the wetting performance, hygroscopic performance, bonding performance, annual cost per unit area, pH value of dust suppression solution, chemical toxicity, and chemical corrosion. Among them, the index characterizing the wetting performance of the solution is the sedimentation wetting time, which is determined by the dust sedimentation experiment; the index characterizing the hygroscopic performance of the solution is the evaporation stability time, which is determined by the evaporation experiment of the solution on the dust surface; the index to characterize the bonding performance of the solution is the surface wind erosion rate, which is determined by the wind erosion experiment of the solution on the dust surface; the toxicity of the solution is evaluated by the LD50 of the solution; the index to characterize the corrosion performance of the solution is the Q235 monthly steel corrosion rate, which is determined by the Q235 steel corrosion test. Corresponding evaluation parameters are determined including sedimentation wetting time, evaporation stabilization time, surface wind erosion rate; annual average use cost per unit area; solution pH value, chemical acute toxicity classification, monthly corrosion rate of Q235 steel, and corresponding standard test methods are also provided. In order to evaluate the comparability of the results, according to the specific requirements of the evaluation index system and the distribution characteristics of the measurement data, the data of each evaluation and detection index are standardized by linear transformation, range transformation and other methods, so that the obtained results are comparable. Considering the differences in the actual performance requirements of dust suppressants in different usage scenarios, the weights of evaluation indicators at all levels can be set independently and flexible. The experimental test data obtained through the example shows that: among the four chemicals selected to participate in the experiment, the comprehensive dust suppression performance score of Triton X-100 solution is in the poor-grade category. The comprehensive dust suppression performances of calcium chloride solution, water, and polyacrylamide solution scored high in the average-grade category. The comprehensive evaluation process is logically correct, and the results are consistent with the phenomena observed in the experiment, consistent with conventional understanding, and have strong credibility. This method can provide a standardized evaluation technique and test process for the comprehensive performance evaluation and comparison of chemical materials and dust suppressants.