Transcriptional modulation of a human monocytic cell line exposed to PM(10) from an urban area

Airborne particulate matter induces oxidative damage, DNA adduct formation and alterations in DNA repair pathways

Air pollution, which includes particulate matter (PM), is classified in group 1 as a carcinogen to humans by the International Agency for Research in Cancer. Specifically, PM exposure has been associated with lung cancer in patients living in highly polluted cities. The precise mechanism by which PM is linked to cancer has not been completely described, and the genotoxicity induced by PM exposure plays a relevant role in cell damage. In this review, we aimed to analyze the types of DNA damage and alterations in DNA repair pathways induced by PM exposure, from both epidemiological and toxicological studies, to comprehend the contribution of PM exposure to carcinogenesis. Scientific evidence supports that PM exposure mainly causes oxidative stress by reactive oxygen species (ROS) and the formation of DNA adducts, specifically by polycyclic aromatic hydrocarbons (PAH). PM exposure also induces double-strand breaks (DSBs) and deregulates the expression of some proteins in DNA repair pathways, precisely, base and nucleotide excision repairs and homologous repair. Furthermore, specific polymorphisms of DNA repair genes could lead to an adverse response in subjects exposed to PM. Nevertheless, information about the effects of PM on DNA repair pathways is still limited, and it has not been possible to conclude which pathways are the most affected by exposure to PM or if DNA damage is repaired properly. Therefore, deepening the study of genotoxic damage and alterations of DNA repair pathways is needed for a more precise understanding of the carcinogenic mechanism of PM.

Biological effect of PM10 on airway epithelium-focus on obstructive lung diseases

Recently, a continuous increase in environmental pollution has been observed. Despite wide-scale efforts to reduce air pollutant emissions, the problem is still relevant. Exposure to elevated levels of airborne particles increased the incidence of respiratory diseases. PM₁₀ constitute the largest fraction of air pollutants, containing particles with a diameter of less than 10 μm, metals, pollens, mineral dust and remnant material from anthropogenic activity. The natural airway defensive mechanisms against inhaled material, such as mucus layer, ciliary clearance and macrophage phagocytic activity, may be insufficient for proper respiratory function. The epithelium layer can be disrupted by ongoing oxidative stress and inflammatory processes induced by exposure to large amounts of inhaled particles as well as promote the development and exacerbation of obstructive lung diseases. This review draws attention to the current state of knowledge about the physical features of PM₁₀ and its impact on airway epithelial cells, and obstructive pulmonary diseases.

Poor Air Quality and Its Association with Mortality in Ho Chi Minh City: Case Study

Along with its rapid urban development, Ho Chi Minh City (HCMC) in recent years has suffered a high concentration of air pollutants, especially fine particulate matters or PM2.5. A comprehensive study is required to evaluate the air quality conditions and their health impact in this city. Given the lack of adequate air quality monitoring data over a large area of the size of HCMC, an air quality modeling methodology is adopted to address the requirement. Here, by utilizing a corresponding emission inventory in combination with The Air Pollution Model-Chemical Transport Model (TAPM-CTM), the predicted concentration of air pollutants is first obtained for PM2.5, NOx, and SO2. Then by associating the pollutants exposed with the mortality rate from three causes, namely Ischemic Heart Disease (IHD), cardiopulmonary, and lung cancer, the impact of air pollution on human health is obtained for this purpose. Spatial distribution has shown a high amount of pollutants concentrated in the central city with a high density of combustion vehicles (motorcycles and automobiles). In addition, a significant amount of emissions can be observed from stevedoring and harbor activities, including ferries and cargo handling equipment located along the river. Other sources such as household activities also contribute to an even distribution of emission across the city. The results of air quality modeling showed that the annual average concentrations of NO2 were higher than the standard of Vietnam National Technical Regulation on Ambient Air Quality (QCVN 05: 2013 40 µg/m3) and World Health Organization (WHO) (40 µg/m3). The annual average concentrations of PM2.5 were 23 µg/m3 and were also much higher than the WHO (10 µg/m3) standard by about 2.3 times. In terms of public health impacts, PM2.5 was found to be responsible for about 1136 deaths, while the number of mortalities from exposure to NO2 and SO2 was 172 and 89 deaths, respectively. These figures demand some stringent measures from the authorities to potentially remedy the alarming situation of air pollution in HCM City.

How Can Design Features and Other Factors Affect the Indoor Air Quality in Inpatient Rooms? Check-Lists for the Design Phase, Daily Procedures and Maintenance Activities for Reducing the Air Concentrations of Chemical Pollution

Indoor Air Quality (IAQ) is one of main topics of Public Health on which international institutions and countries are taking action. With regards to healing architectures, several studies have reported data analysis and case studies to improve users' health (patients, and medical and administrative staffs), but there are not enough regarding volatile organic compounds (VOCs). Regarding chemical pollution of indoor air, the Scientific Community has highlighted that there are several factors that affect the IAQ, in particular the design and management, and energetic efficiency, of inpatient wards. Several stakeholders, from the designers to the managers, are responsible for the indoor air in healing environments. Supported by analysis of the State of the Art and the main factors that influence the heterogeneous scenario of inpatient wards, the paper presents three check-lists, designed for supporting the stakeholders during the design phase, or for the daily procedures and maintenance activities, for pre-assessment of factors that affect chemical pollution, and for the definition of strategies to be applied. In fact, in such environments IAQ assumes a particular meaning and importance, both for the vulnerability of the patients and for the long time spent by the sanitary staff. The multidisciplinary approach emphasizes the continuous need for interdisciplinary knowledge and skills aimed at finding solutions able to protect users' health status (including patients, workers and visitors), especially in the field of the indoor air issue.

Ambient particulate matter exposure and cardiovascular diseases: a focus on progenitor and stem cells

Air pollution is a major challenge to public health. Ambient fine particulate matter (PM) is the key component for air pollution, and associated with significant mortality. The majority of the mortality following PM exposure is related to cardiovascular diseases. However, the mechanisms for the adverse effects of PM exposure on cardiovascular system remain largely unknown and under active investigation. Endothelial dysfunction or injury is considered one of the major factors that contribute to the development of cardiovascular diseases such as atherosclerosis and coronary heart disease. Endothelial progenitor cells (EPCs) play a critical role in maintaining the structural and functional integrity of vasculature. Particulate matter exposure significantly suppressed the number and function of EPCs in animals and humans. However, the mechanisms for the detrimental effects of PM on EPCs remain to be fully defined. One of the important mechanisms might be related to increased level of reactive oxygen species (ROS) and inflammation. Bone marrow (BM) is a major source of EPCs. Thus, the number and function of EPCs could be intimately associated with the population and functional status of stem cells (SCs) in the BM. Bone marrow stem cells and other SCs have the potential for cardiovascular regeneration and repair. The present review is focused on summarizing the detrimental effects of PM exposure on EPCs and SCs, and potential mechanisms including ROS formation as well as clinical implications.

Effects of coarse chalk dust particles (2.5-10 μm) on respiratory burst and oxidative stress in alveolar macrophages

The main aim of the present study was to examine in vitro responses of rat alveolar macrophages (AMs) exposed to coarse chalk dust particles (particulate matter in the size range 2.5-10 μm, PM(coarse)) by respiratory burst and oxidative stress. Chalk PM(coarse)-induced respiratory burst in AMs was measured by using a luminol-dependent chemiluminescence (CL) method. Also, the cell viability; lactate dehydrogenase (LDH) release; levels of cellular superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), malondialdehyde (MDA), and acid phosphatase (ACP); plasma membrane ATPase; and extracellular nitric oxide (NO) level were determined 4 h following the treatment with the different dosages of chalk PM(coarse). The results showed that chalk PM(coarse) initiated the respiratory burst of AMs as indicated by strong CL, which was inhibited by diphenyleneiodonium chloride and L-N-nitro-L-arginine methyl ester hydrochloride. It suggested that chalk PM(coarse) induced the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in AMs. This hypothesis was confirmed by the fact that chalk PM(coarse) resulted in a significant decrease of intracellular SOD, GSH, ACP, and ATPase levels and a notable increase of intracellular CAT, MDA content, and extracellular NO level, consequently leading to a decrease of the cell viability and a increase of LDH release. It was concluded that AMs exposed to chalk PM(coarse) can suffer from cytotoxicity which may be mediated by generation of excessive ROS/RNS. Graphical Abstract The possible mechanism of coarse chalk particles-induced adverse effects in AMs.

Evaluating the genotoxicity of urban PM2.5 using PCR-based methods in human lung cells and the Salmonella TA98 reverse test

A number of compounds found in particulate matter with an aerodynamic diameter <2.5 (PM2.5) can interact with DNA either directly or after enzymatic transformation to induce DNA modifications. These particulate matter (PM)-induced alterations in DNA may be associated with increased frequencies of pollution-associated diseases, such as lung cancer. In the present study, we applied different methods to assess the mutagenicity and genotoxicity of monthly PM2.5 organic extracts collected over a full year. We used the Salmonella assay, exposed cultured human embryonic lung fibroblasts and applied extracellular lactate dehydrogenase (LDH) and 2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxyanilide inner salt (XTT) assays to assess the cytotoxicity of PM2.5 on the cells. We assessed both the expression levels of a number of DNA repair genes (using qRT-qPCR) and the genetic profile of the treated cells compared to the control. The expression levels of XRCC1 and APE1, which are involved in the first steps of base excision repair, as well as ERCC1, XPA and XPF, which encode nucleotide excision repair subunits, were analysed. The monthly mean of the PM2.5 collected was 35.16 ± 22.06 μg/m(3). The mutagenicity of PM2.5 to TA98 was 46 ± 50 net revertants/m(3), while the mutagenicity to TA98 + S9 was 17 ± 19 net revertants/m(3). The mean IC50 values were 2.741 ± 1.414 and 3.219 ± 2.764 m(3) of equivalent air in the XTT and LDH assays, respectively. A marked and significant increase in APE1 expression levels was observed in the exposed cells. This effect was also significantly correlated with mutagenicity (p < 0.01). No induced AFLP fragment profile alterations were detected. The proposed approach seems to be useful for integrated evaluation and for highlighting the mechanisms inducing DNA damage.