Occupational exposure to respirable dust from the coal-fired power generation process: sources, concentration, and health risk assessment

A comprehensive review of toxicity of coal fly ash and its leachate in the ecosystem

Coal fly ash (CFA), a byproduct of coal combustion, is a hazardous industrial solid waste. Its excessive global production, coupled with improper disposal practices, insufficient utilization and limited awareness of its inherent hazards, poses a significant threat to both ecological environment and human health. Based on the physicochemical properties of CFA and its leachates, we elucidate the forms of CFA and potential pathways for its entry into the human body, as well as the leaching behavior, maximum tolerance and biological half-life of toxic elements present in CFA. Furthermore, we provide an overview of current strategies and methods for mitigating the leaching of these harmful elements from CFA. Moreover, we systemically summarize toxic effect of CFA on organisms across various tiers of complexity, analyze epidemiological findings concerning the human health implications resulting from CFA exposure, and delve into the biotoxicological mechanisms of CFA and its leachates at cellular and molecular levels. This review aims to enhance understanding of the potential toxicity of CFA, thereby promoting increased public awareness regarding the disposal and management of this industrial waste.

Probabilistic health risk assessment of occupational exposure to crystalline silica in an iron foundry in Urmia, Iran

This study aimed to quantify the exposure of foundry workers to crystalline silica and associated cancer and non-cancer health risks using a probabilistic approach. Breathing zone air samples were collected according to the NIOSH 7602 method and analyzed using Fourier transform infrared spectroscopy. The health risks posed by crystalline silica were then assessed using the EPA-developed inhalation risk assessment model and Monte Carlo simulation. The sensitivity analysis was also conducted to determine the contribution of input parameters to the health risks. The mean concentration of crystalline silica in six foundry stations ranged from 0.029 to 0.064 mg m-3, exceeding the occupational exposure limits. The average values of cancer risks were greater than the USEPA level, i.e., 1E - 6 in all workstations of the foundry. Workers in sand preparation and molding stations suffered the greatest cancer risks, with the mean value of 2.35E - 5 and 2.10E - 5, respectively. Non-cancer hazard quotient exceeded 1 in all foundry stations ranging from 1.56 (in melting and pouring) to 3.37 (in sand preparation). The 95% upper-bound values of the health risks decreased by 77.52% and 56.77%, assuming the use of engineering controls and wearing respirators by workers, respectively. Sensitivity analyses indicate that concentration was the most sensitive factor contributing to the carcinogenic (46.13%) and non-carcinogenic (67.08%) risks. These findings can aid managers in gaining a better understanding of the silica risks faced by foundry workers and the role of engineering controls and respirators in protecting workers' health.

Health impacts of air pollution in Chinese coal-based clean energy industry: LCA-based and WTP-oriented modeling

The evolution of energy system occupies an important position in economic development and quality of life. Influenced by the energy endowment in China, developing the coal-based clean energy industry has been regarded as a guaranteed path to realizing the clean and efficient use of coal resources. However, an evaluation paradigm that could systematically assess the health impacts of airborne pollution in this industry is still lacking, which is our concern. Combining with life cycle analysis, probabilistic risk models, and health impact models, this study proposes a series of models which are consistent enough to unite pollutant concentration, health risk, and health impact, and equip assessment results with more intuitive significance of life and economic loss. Further, case studies for three typical clean coal technologies, namely, coal mining, coal-fired power generation, and coal liquefaction, are presented to verify the reliability of these models. Results show that the most severe health impact occurred at the worksite of driving face, the substage of coal combustion, and coal mining and processing, respectively, for the three technologies. Further, coal dust brought about the greatest pollution to coal mining and coal liquefaction, and for coal-fired power generation, SO₂, NO₂, and PM₁₀ were the commonest and toughest pollutants. In conclusion, the proposed evaluation paradigm can help to find out the worksite, substage, and airborne pollutant with the most severe impact and is more intuitive to provide references for minimizing or eliminating environmental pollution. Additionally, three aspects of implications are confirmed in this study, namely, social mobilization promoting, government policy making, and environmental pollution prejudging.

Modeling health impacts of air pollutant emissions from the coal-fired power industry based on LCA and oriented by WTP: a case study

Coal-fired power plants are one of the major sources of coal consumption in China; they discharge various air pollutants and cause serious human health damage. There is an urgent need to focus on the associated health effects. Thus, this study aims to advance an integrated life cycle assessment (LCA)-based health damage model to quantify the health burden of air pollutant emissions from coal-fired power generation (CFPG) and to achieve an economic interpretation of health damage. A case study of the Zaozhuang coal-fired power project was conducted to better visualize and mitigate the impacts. The results reveal that willingness to pay (WTP) for health damage caused by the CFPG project in 1 year amounted to USD 15.71 million, and the total amount of life lost was 155.81 years. During the CFPG process, coal combustion caused the most health damage, respiratory disease was the type of damage with the greatest influence on health, and SO₂ was the air pollutant that causes the most serious health damage. The model developed in this study can be broadly applied to assess the potential life loss due to air pollutant emissions from CFPG systems. The identified key points for health damage prevention can also be used as practical solutions for decision-making regarding the prioritization of control sources for environmental management.

Occupational Dust Hazards and Risk Assessment of Coal-Fired Thermal Power Plants of Different Capacities - China, 2017-2019

What is already known about this topic?

Silica dust and coal dust are the main occupational hazards in coal-fired thermal power plants, which mainly exist in coal transportation workplaces, combustion milling workplaces, and ash removal workplaces.

What is added by this report?

The overall environmental and personal dust exposure levels decrease with an increase in the capacity of coal-fired thermal power plants, the overall dust hazard risk level of the workforce in coal-fired is Medium.

What are the implications for public health practice?

Dust management should be conducted in the coal-fired thermal power plant in 300 million watt units because it has the highest dust exposure level, and ash removal workplaces and combustion milling workplaces are key control points for dust hazards.

Respiratory Symptoms and Diminished Lung Functions Associated with Occupational Dust Exposure Among Iron Ore Mine Workers in Iran

Background:

Dust exposure at quarry mines is inevitable and can result in poor air quality. This research aimed to assess pulmonary symptoms and lung functions of dust-exposed workers at an iron-ore mine in eastern Iran.

Methods:

An environmental cross-sectional study sampled 174 dust-exposed mine workers and 93 unexposed administrative employees as the reference group. A standardized questionnaire on respiratory symptoms was completed in accordance with recommendations of the American Thoracic Society(ATS). Calibrated spirometer measured Pulmonary Function Tests (PFTs). Data were analyzed via SPSS-21, integrating independent samples t-test, Chi-square and linear or logistic-regression models.

Results:

There was no significant variation between dust-exposed and reference groups in terms of age, weight, height, work experience and the number of smokers (P>0.05). Mean levels of exposure to inhalable and respirable mineral-dust were 15.09±2.34 and 3.45±2.57 mg/m³ respectively. Pulmonary capacities of dust-exposed group were considerably decreased as compared to others (Forced Vital Capacity [FVC] 86.55±13.77 vs. 105.05±21.5; Forced Expiratory Volume in 1 second [FEV1] 88.06±16.8 vs. 105.81±21.55; FEV1/FVC 103.03±18.17 vs. 93.3±12.49; and Peak Expiratory Flow [PEF] 89.82±22.58 vs. 98.09±20.60) (P<0.001); with a higher prevalence of cough (P=0.041), wheezing (P=0.032), and dyspnea (P=0.035) among formers. Age along with exposure to respirable-dust significantly reduced FVC, FEV1 and FEV1/FVC. Cigarette consumption attenuated FVC and FEV1 on an average of 5 to 9 units.

Conclusion:

Controlled occupational dust-exposure is a definitive pre-requisite to reduce respiratory problems among quarry workers, with an explicit consideration towards mineral- mine workers. Modifiable accomplices like smoking and non-compliance of PPEs usage should be amicably resolved.