Investigation and Comparison of In Vitro Genotoxic Potency of PM10 Collected in Rural and Urban Sites at Tehran in Different Metrological Conditions and Different Seasons

Elemental composition of atmospheric PM10 during COVID-19 lockdown and recovery periods in Moscow (April-July 2020)

Changes in the concentrations of PM10-bound potentially toxic elements (PTEs) during the COVID-19 lockdown period and after the revocation of restrictions were analyzed using the data received at the Aerosol Complex of Moscow State University in April-July 2020. During the lockdown, the input of biomass combustion products enriched in PTEs from the Moscow region hindered the decrease in pollutant concentrations. After the introduction of the self-isolation regime, lower concentrations of most PTEs occurred due to the decrease in anthropogenic activity and the rainy meteorological conditions. After the revocation of restrictive measures, the PTE concentrations began to increase. Multivariate statistical analysis (APCA-MLR) identified the main sources of atmospheric pollutants as urban dust, non-exhaust traffic emissions, and combustion and exhaust traffic emissions. PM10 particles were significantly enriched with Sb, Cd, Sn, Bi, S, Pb, Cu, Mo, and Zn. The total non-carcinogenic and carcinogenic risks, calculated according to the U.S. EPA model, decreased by 24% and 23% during the lockdown; after the removal of restrictions, they increased by 61% and 72%, respectively. The study provides insight into the PTE concentrations and their main sources at different levels of anthropogenic impact.

Thermal stress and TiO2 nanoparticle-induced oxidative DNA damage and apoptosis in mouse hippocampus

Titanium dioxide (nano-TiO₂) is used abundantly in various industrial products and novel medical therapies. In addition, the impact of climate change on the health and safety will undoubtedly increase in the future. However, the effects of exposure to these nanoparticles and heat stress on hippocampal DNA damage and apoptosis remain unclear. This study was conducted to evaluate the DNA damage and apoptosis in the hippocampal tissue and the physiological responses in mice induced by intraperitoneal (i.p.) administration of TiO₂ nanoparticles (NPs) and heat stress for 14 consecutive days. The results showed that heat stress and TiO₂-NPs were induced in the mouse hippocampus that led to hippocampal reactive oxygen species generation, oxidative damage of DNA, and apoptosis in a partly dose-dependent manner, especially at very hot temperature. High doses of nanosized TiO₂ and severe heat stress significantly damaged the function of the hippocampus, as shown in the comet assay and apoptosis tests. The results of this study may provide data for appropriate measures to control and assess the risk of nano-TiO₂ and thermal stress hazards to human health, especially workers. Safety guidelines and policies should be considered when handling nanomaterials in a hot environment.

Real-time chemical composition of ambient fine aerosols and related cytotoxic effects in human lung epithelial cells in an urban area

Particulate matter with aerodynamic diameters ≤1 μm (PM₁) in the atmosphere, especially that which is emitted from anthropogenic sources, can induce considerable negative effects on the cardiopulmonary system. To investigate the chemical emission characteristics and organic sources in Yuen Long (Hong Kong), both offline and online approaches for PM₁ samples were applied by filter-based samplers and a Quadrupole Aerosol Chemical Speciation Monitor (Q-ACSM), respectively. The toxicological effects on human A549 lung alveolar epithelial cells were investigated, and associations between cytotoxicity and organic sources and compositions were evaluated. The organics from the Q-ACSM measurement were the largest contributor to submicron aerosols in both seasons of our study, and the mass fraction was higher in winter (60%) than it was in autumn (46%). Regarding organic sources, the mass fraction of hydrocarbon-like organics (HOA) increased from 7% in autumn to 38% in winter, whereas cooking organics (COA) decreased from 30% in autumn to 18% in winter, and oxygenated organics (OOA) decreased from 63% to 45%. Organic compounds contributed more during pollution episodes, and more secondary ions were formed by means of the oxidation process. Oxidative and inflammatory responses in A549 cells were found with PM₁ exposures; the differences in chemical compositions resulted in the higher cytotoxicity in winter than autumn. The cooking organic aerosol in residential area was significantly correlated with cell inflammation. Both elemental carbon and specific inorganic ions (SO₄^2- and Mg²⁺) contributed to the intracellular cytotoxicity. This study demonstrated that specific atmospheric particulate matter chemical properties and sources can trigger distinct cell reactions; the inorganic ions from cooking emissions cannot be disregarded in terms of their pulmonary health risks in residential areas.

Distributing and assessing fluoride health risk in urban drinking water resources in Fars Province, Iran, using the geographical information system

Excessive fluoride intake has been reported in many studies, which can lead to diseases such as autism, mental retardation, low birth weight, reproductive disorder, as well as dental and bone fluorosis. The potential risk assessment of fluoride intake for the health of people living in Fars Province, Iran, is investigated. Hence, 1700 drinking water samples were taken from April 2018 to March 2020 in four seasons in 29 cities of Fars Province and were analyzed. Non-carcinogenic health risks of exposure to fluoride through drinking water were evaluated. Moreover, the spatial distribution maps of fluoride and hazard quotient (HQ) risk index were prepared using GIS software. The results showed that the concentration of fluoride in the drinking water of the studied area was in the range of 0.086 to 2.61 mg/L. Accordingly, in 48.27% of the cities, fluoride was in the range below the national and international standards, 34.48% of the cities were in the permissible range of 0.5 to 1.5 mg/L, and 17.24% of the urban areas of the province had fluoride contents above the permissible range. Hazard quotient index had the health risk of HQ > 1 in 27.58% of children, 17.24% of teenagers, and 10.34% of adults in the urban areas of Fars Province. In the cities with HQ > 1, there was risk of diseases associated with excessive fluoride intake. Therefore, it is necessary to replace water supply sources in these cities.

Viral respiratory infections and air pollutants

Air pollution is a public health issue of global importance and a risk factor for developing cardiorespiratory diseases. These contaminants induce reactive oxygen species (ROS) and increased pro-inflammatory cytokines such as IL-1β, IL-6, and IL-8, triggering the inflammatory response that alters cell and tissue homeostasis and facilitates the development of diseases. The effects of air pollutants such as ozone, particulate matter (PM10, PM2.5, and PM0.1), and indoor air pollutants on respiratory health have been widely reported. For instance, epidemiological and experimental studies have shown associations between hospital admissions for individual diseases and increased air pollutant levels. This review describes the association and relationships between exposure to air pollutants and respiratory viral infections, especially those caused by the respiratory syncytial virus and influenza virus. The evidence suggests that exposure to air contaminants induces inflammatory states, modulates the immune system, and increases molecules' expression that favors respiratory viruses' pathogenesis and affects the respiratory system. However, the mechanisms underlying these interactions have not yet been fully elucidated, so it is necessary to develop new studies to obtain information that will allow health and policy decisions to be made for the adequate control of respiratory infections, especially in the most vulnerable population, during periods of maximum air pollution.

The use of multi-criteria method in the process of threat assessment to the environment

Measurements of the content of trace elements, including toxic and carcinogenic metals, in various fractions of particulate matter PM are an important element of environmental monitoring and research involving their impact on human health. The article presents the measurement results of atmospheric composition of suspended dust (PM₁₀), respirable fraction (PM_2.5) and submicron particulate matter (PM₁) collected with the Dekati PM₁₀ cascade impactor. Samples were collected in the vicinity of four working power plants (from 28 May to 23 September 2014) and four coking plants (from 4 May to 28 August 2015) in Upper Silesia, Poland. The qualitative and quantitative analysis of the solutions: arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb) and selenium (Se) obtained for individual fractions was performed by inductively coupled plasma mass spectrometry, using the apparatus ICP-MS. The research results were used to determine a synthetic assessment of the threat to the anthropogenic environment and for the preparation of the ranking of the measured points.

Input Parameters for Airborne Brake Wear Emission Simulations: A Comprehensive Review

Non-exhaust emissions, generated by the wear of brake systems, tires, roads, clutches, and road resuspension, are responsible for a large part of airborne pollutants in urban areas. Brake wear accounts for 55% of non-exhaust emissions and significantly contributes to urban health diseases related to air pollution. A major part of the studies reported in the scientific literature are focused on experimental methods to sample and characterize brake wear particles in a reliable, representative, and repeatable way. In this framework, simulation is an important tool, which makes it possible to give interpretations of the experimental results, formulate new testing approaches, and predict the emission produced by brakes. The present comprehensive literature review aims to introduce the state of the art of the research on the different aspects of airborne wear debris resulting from brake systems which can be used as inputs in future simulation models. In this review, previous studies focusing on airborne emissions produced by brake systems are investigated in three main categories: the subsystem level, system level, and environmental level. As well as all the information provided in the literature, the simulation methodologies are also investigated at all levels. It can be concluded from the present review study that various factors, such as the uncertainty and repeatability of the brake wear experiments, distinguish the results of the subsystem and system levels. This gap should be taken into account in the development of future experimental and simulation methods for the investigation of airborne brake wear emissions.

Associations between short term exposure to ambient particulate matter from dust storm and anthropogenic sources and inflammatory biomarkers in healthy young adults

This study examined the association between particulate matter from anthropogenic and natural sources and inflammatory biomarkers, including hs-CRP, IL-6, sTNF-RII, and WBCs, in two groups of healthy young subjects. We followed up subjects of two panels (16 to 22 years old), including 22 subjects selected from the urban area (Tehran city) with high-level pollution background and 22 subjects selected from the rural area (Ahmadabad) with low-level pollution background. In each group, we collected 4 times blood samples in various air pollution conditions, In the subjects of the urban group, there was a substantial difference (p < 0.05) between inversion days and cold season control days, and between dust storm days and warm season control days for concentrations of hs-CRP, IL-6, and WBCs biomarkers. In the subjects of the rural group, a significant difference could be detected in the concentration of hs-CRP, IL-6, and WBCs biomarkers (p < 0.05) between inversion days and cold season control days, and between dust storm and warm control days. We found that the difference in concentrations of hs-CRP, IL-6, and WBCs biomarkers between dust storm days and warm control conditions in the rural group were higher than the difference in inversion and cold control conditions, which can be attributed to low background air pollution in the rural area. In the urban area, the health effect of anthropogenic sources of PM is higher than the dust storm condition, which can be attributed to the stronger effect of anthropogenic pollution effect.

In-vitro human lung cell injuries induced by urban PM2.5 during a severe air pollution episode: Variations associated with particle components

Environmental air pollutants pose significant threats to public health, especially the toxicity and diseases caused by the atmospheric fine particulate matters (PM_2.5). Since the health risks vary with both the concentrations and compositions of PM_2.5 which are determined by aerosol sources, how are their toxic effects relevant to the pollution level becomes an important issue, such as the haze episodes covering clean and polluted days. With the transition from non-pollution to pollution stage, daily PM_2.5 samples were collected from both the urban and industrial areas of Nanjing city, eastern China, covering a typical haze event in autumn-winter. Their unpropitious effects on human lung epithelial cells (A549) were compared by in vitro toxicity assays and chemical component analysis. Both air levels and cytotoxic effects of PM_2.5 varied with the transition of haze event. Although the concentration of PM_2.5 in air is of course the highest in pollution stage driven by local stable meteorological condition, unit mass of them posed higher toxicity (lower cell viability and higher IL-6) but induced lower cell oxidative (evidences of ROS and NQO1 mRNA expression) and inflammatory cytokine TNF-α responses than those particles during non-pollution stage. These patterns were explained by the metals and water-soluble components decreased with the haze development. Non-soluble particulate carbonaceous aerosol compositions might play a significant role in inducing cytotoxicity. Moreover, the regional pattern of episode pollution weakened the spatial variation within a city scale. Since the haze development intensified both the quantity and toxicity of PM_2.5 in air, the health risks of overall aerosol exposure were synthetically amplified during haze weather, so the increased air particles with higher toxic components from fuel combustion sources should be key targets of pollution control.

The cytotoxicity and genotoxicity of PM2.5 during a snowfall event in different functional areas of a megacity

Atmospheric fine particulate matter (PM_2.5) can harm human health, but the chemical composition and toxicity of PM_2.5 pollution might vary with weather conditions. In order to investigate the impacts of snowfall weather on aerosol characteristics and toxicity by changing particle sources and components, the daily PM_2.5 samples were collected before, during, and after a snowfall event in urban, industrial, suburban, and rural areas of Nanjing city in eastern China, for both chemical composition analysis and cytotoxicity tests. After 24 h exposure to these PM_2.5, the cell activity, oxidative stress indicators and inflammatory factor expression levels of human lung epithelial cells A549 were measured by ELISA, and DNA damage was determined by comet assay. Although the concentrations of PM_2.5 in the air were reduced during snowfall, they posed stronger cytotoxicity, genetic toxicity and inflammatory responses to A549 cells. Related to the elevated mass concentrations of some components accumulated in PM_2.5 during snowfall, As, Co, Cr, Sr, V, water-soluble Na⁺ and Ca²⁺ showed positive correlations with toxicity indicators. Therefore, snowfall will clean air by deposition, but also make the PM_2.5 components remaining in air mostly anthropogenic by covering ground soil/dust, thus increase the particle's mass-based cytotoxicity and their health risks still cannot be ignored, such as the heavy metals and water-soluble ions from automobile exhaust and coal combustion.

The acute effects of short term exposure to particulate matter from natural and anthropogenic sources on inflammation and coagulation markers in healthy young adults

Airborne particulate matter is associated with increasing the risk of cardiovascular diseases. The purpose of this study was to investigate the association between air pollution conditions and MDA, vWF, and fibrinogen markers in the blood of two panels of healthy young individuals in an urban area in Tehran city with a high air pollution background and another group was living in a rural area (Ahmad Abad Mostofi), with a low air pollution background. In each group, 4 blood samples were taken as follows: one in inversion days, the second in winter, but during the existence of normal condition in terms of air pollution, the third sample in the spring during the normal condition in terms of air pollution and the fourth sample during the dust storm conditions. In the urban and rural groups, there was a significant difference between the concentration of MDA, vWF, fibrinogen between inversion and cold season control conditions, and between dust storm conditions and warm season control conditions (p < 0.05). The results showed that the association of dust storm condition on the measured biomarkers was stronger than the inversion condition, which health consideration in the dust conditions be taken into account similar to the inversion conditions.

Chemical composition of PM10 and its effect on in vitro hemolysis of human red blood cells (RBCs): a comparison study during dust storm and inversion

PURPOSE

This study aimed to investigate chemical composition of PM₁₀ (particulate matter with aerodynamic diameter ≤ 10 μm) during dust storm and inversion in Tehran and hemolysis effects.

METHODS

PM₁₀ was sampled in Tehran, Iran, during dust storm and inversion conditions. Water soluble ions (F¯, Cl¯, NO₂¯, NO₃¯, SO₄¯², Na⁺, K⁺, NH₄ ⁺, Ca⁺², Mg⁺²) and elements (Al, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Se, Sn, Sr, V, Zn, Pt, Rh, Pd, As and Si) were analyzed by ion chromatograph (IC) and inductively coupled plasma optical emission spectrometer (ICP-OES), respectively. Hemolysis was examined as in vitro at PM₁₀ concentrations of 50-300 μg/ml.

RESULTS

Daily average of PM₁₀ concentrations in dusty and inversion days were 348.40 and 220.54 μg/m³, respectively. Most prevalence ionic components were NO₃¯, Cl¯, SO₄¯² and Ca⁺² during dust storm and SO₄¯², NO₃¯, Cl¯ and NH₄ ⁺ during inversion. Si, Fe and Al had the maximum values in both conditions. Particles associated with both conditions induced hemolytic responses. PM₁₀ from dusty day showed a higher hemolysis percent (10.24 ± 4.67%) than inversion (9.08 ± 5.47%), but this difference was not significant (p = 0.32). Hemolytic effects were significantly intensified by increased PM concentrations (p < 0.001) in a dose-response manner.

CONCLUSIONS

As the results, chemical composition of sampled particles from inversion days and dust storm was different from each other. Hemolytic effects of particles during dust storm were more than inversion days. However, this difference was not statistically significant.