Toxic Air Pollutants Research Articles

School students’ awareness on air pollution and its health effects in the Sultanate of Oman

The current study aimed to investigate the level of Omani school students’ awareness of air pollution and its health effects due to gender and grade variables. A study was conducted in four governorates in Oman, viz. Muscat, Al Dakhiliyah, north and south Al Batinah, in the 2022/2023 academic year. A closed online questionnaire was used with a total of 1,337 respondents from grades 9<sup>th</sup>, 10<sup>th</sup>,<sup> </sup>& 11<sup>th</sup>. The results of the study showed that the level of students’ awareness regarding air pollution and its health effects was moderate. Significant differences in students’ awareness of air pollution and its health effects due to gender and grade variables were obtained. Female students were more vulnerable than males to the effects of air pollution, hence they were significantly careful about air quality when doing outdoor sports activities. In contrast, male students’ awareness of the schools’ role regarding air pollution awareness and reduction actions was significantly higher than female students. Social media was a main source of access to information about air pollution. Inhaling contaminated air was the most common route of exposure to the toxic air pollutants reported by participants.

Enhanced VOCs adsorption on Group VIII transition metal-doped MoS2: A DFT study

Volatile organic compounds (VOCs) represent a significant category of toxic and harmful air pollutants. Among the various abatement techniques available for VOCs, adsorption technology is widely recognized as a cost-effective solution. In this study, density functional theory (DFT) was employed to calculate and compare the adsorption capacities of six typical VOCs on pristine MoS2 and MoS2 modified with Group VIII (MVIII) transition metals atoms. It is found that MVIII-MoS2 monolayer demonstratesa significant enhancement in adsorption capabilities for VOCsrelative to pristine MoS2. Among these Group VIII transition metals atoms, Fe, Ru and Os atoms exhibited the most significant VOCs adsorption enhancement, with Fe atoms demonstrating a particularly pronounced effect. This suggests a synergistic interaction between the metal dopants and the substrate. Density of states (DOS) and charge density difference analyses provided further insights into the mechanisms underlying improved adsorption capability. Interestingly, the introduction of MVIII atoms results in the emergence of a novel state density within the surface state of MoS2, thereby facilitating enhanced electron transfer between VOCs and the substrate. Charge density difference calculations further corroborated these findings, with certain configurations exhibiting significant electron cloud overlap. Such modification leads to more active electron transfer, thereby increasing the substrate’s affinity for VOC molecules and consequently improving the adsorption efficiency. The findings not only enhance the comprehension of VOC adsorption mechanisms on MoS2 but also underscore the potential of metal-doped two-dimensional materials for environmental applications.

Toxic air pollution and cognitive decline: Untangling particulate matter

There is increasing evidence indicating air pollution is an important factor influencing the aging brain. However, much of this work measures air pollution using particulate matter (PM). Yet we know that the chemical components of PM are not consistent across space or time. Rather, the possible chemical mixtures of PM vary and are therefore not reliably measuring the same thing across studies. In this study we attempt to disentangle the effects of the components of measured PM by using estimates of concurrent exposures of 415 industrial air toxics, as well as 44 neuro- and developmental toxics. Using bivariate latent curve models, we leverage individual level panel data from the bi-annual Health and Retirement Study to test how these exposures relate to cognitive score trajectories of respondents across the years 2002–2012. We find that more exposure to neurotoxics was associated with faster rate of cognitive decline by 1.09 points (p < 0.05).

Effect of fluoride toxicity on morphological, biochemical and physiological parameters in different oat cultivars

Fluoride is one of the most highly toxic soil and air pollutant prevalent in aquatic as well as terrestrial ecosystems. It seriously affects crop plant quality and productivity worldwide. Although a crop with great nutritional value; oats are susceptible to a variety of abiotic stresses. In the current study, the responses of six oat cultivars (JHO-99-1, JHO-2009, BJ-2012, KANT, JHO-822, and JHO-2000) to fluoride stress on growth measurements, photosynthetic pigments, and photosynthetic parameters have been studied. The fluoride (200 and 400 mg/kg) was added to the soil artificially, seeds were sown and the pots were kept under controlled conditions. Another set of plants without the fluoride treatment (0 mg/kg) were labeled as control. The experiment was conducted in a plant growth chamber and fluoride was artificially added to the soil prior to seeding. All six oat cultivars subjected to fluoride stress exhibited an overall decrease in plant growth when compared to the control. Further under fluoride stress, while the oat cultivars also showed a decrease in chlorophyll content and different photosynthetic parameters but on the contrary the antioxidant activities were increased. While the cultivar JHO-822 was most affected under fluoride stress, JHO-99-1 showed tolerance toward fluoride toxicity in comparison to other cultivars JHO-2009, BJ-2012, KANT, JHO-822, and JHO-2000. It is concluded that the tolerance or susceptibility of a cultivar to fluoride can be well correlated with various parameters studied in the present study.

Atmospheric NO2 enhances tolerance to low temperature by promoting nitrogen and carbon metabolism in tobacco

With abnormal global climate change and the frequent occurrence of extreme weather, low-temperature stress poses an increasingly serious threat to the diversity of plants. Low temperatures accompanied by limitations in nitrogen cause a series of morphological, physiological, and molecular changes in plants. Nitrogen dioxide (NO2) is a gas that is considered to be a toxic air pollutant. However, NO2 in the atmosphere can be absorbed by plants and participate in nitrogen metabolism. In this study, tobacco (Nicotiana tabacum L.) seedlings were fumigated with a concentration of 4 µL·L−1 NO2 at 4 ℃ for 10 days. NO2 promoted the glutamine synthetase-glutamate synthase (GS/GOGAT) pathway in the leaves at low temperatures, which transforms more organic nitrogen that can be directly utilized by the plants, and improves the skeleton for carbon metabolism. Moreover, gamma-aminobutyric acid (GABA) was generated through the ornithine and glutamate pathways, and the biosynthesis of proline was also enhanced after treatment with NO2. Together, these compounds regulate the osmotic balance of tobacco leaf cells under low-temperature stress. NO2 activated the ascorbate-glutathione (AsA-GSH) cycle in the leaves under low-temperature stress, and this antioxidant enzyme system synergistically removed the intracellular free radicals that result from reactive oxygen species. Additionally, NO2 significantly increased the content of nitric oxide (NO) in the leaves under low-temperature stress and enhanced the opening of stomata, thus, improving photosynthesis in the leaves. The biosynthesis of chlorophyll in the leaves was inhibited by low-temperature stress, but NO2 promotes the biosynthesis of chlorophyll directly or through the nitric acid signaling pathway and improves the ability of plants to capture light energy. NO2 also alleviates the photoinhibition induced by cold stress by regulating photosynthetic electron transfer and absorbing more energy for the assimilation of photosynthetic carbon. This improves the photochemical efficiency of tobacco leaves. In conclusion, NO2 enhanced the tolerance of tobacco seedlings to low temperature by regulating nitrogen metabolism, the osmotic balance, antioxidant system, and photosynthesis.

Water Microdroplets in Air: A Hitherto Unnoticed Natural Source of Nitrogen Oxides.

Water microdroplets are widespread in the atmosphere. We report a striking observation that micron-sized water droplets obtained from zero-volt spray sources (sonic spray, humidifier, spray bottle, steamer, etc.) spontaneously generate nitrogen oxides. The mechanistic investigation through the development of custom-designed sampling sources combined with mass spectrometry and isotope labeling experiments confirmed that air nitrogen reacts with the water at the air-water interface, fixing molecular nitrogen to its oxides (NO, NO2, and N2O) and acids (HNO2 and HNO3) at trace levels without any catalyst. These reactions are attributed to the consequence of an experimentally detected feeble corona discharge (breakdown of air) at the air-water interface, likely driven by the high intrinsic electric field at the surface of water microdroplets. The extent of this corona discharge effect varies depending on the pH, salinity/impurity, size, speed, and lifetime of microdroplets in the air. Thus, this study discloses that the air-water interface of microdroplets breaks the strong chemical bond of nitrogen (N2), producing nitrogen oxides in the environment, while lightning strikes and microbial processes in soil are considered their dominant natural sources. As nitrogen oxides are toxic air pollutants, their spontaneous formation at the air-water interface should have important implications in atmospheric reactions, requiring further investigations.

Modification of the incinerator to prevent the emission of toxic air pollutant in biomedical waste incineration process at Base Hospital Udugama

Modification of the incinerator to prevent the emission of toxic air pollutant in biomedical waste incineration process at Base Hospital Udugama

Environmental Risk Factors in Autism Spectrum Disorder: A Narrative Review.

Existing evidence indicates that environmental factors might contribute up to 50% of the variance in autism spectrum disorder (ASD) risk. This structured narrative review offers a comprehensive synthesis of current knowledge on environmental risk factors in ASD, including evaluation of conflicting evidence, exploration of underlying mechanisms, and suggestions for future research directions. Analysis of diverse epidemiological investigations indicates that certain environmental factors, including advanced parental age, preterm birth, delivery complications, and exposure to toxic metals, drugs, air pollutants, and endocrine-disrupting chemicals, are linked to an increased ASD risk through various mechanisms such as oxidative stress, inflammation, hypoxia, and its consequences, changes in neurotransmitters, disruption of signaling pathways and some others. On the other hand, pregnancy-related factors such as maternal diabetes, maternal obesity, and caesarian section show a weaker association with ASD risk. At the same time, other environmental factors, such as vaccination, maternal smoking, or alcohol consumption, are not linked to the risk of ASD. Regarding nutritional elements data are inconclusive. These findings highlight the significance of environmental factors in ASD etiology and emphasize that more focused research is needed to target the risk factors of ASD. Environmental interventions targeting modifiable risk factors might offer promising avenues for ASD prevention and treatment.

Exposure to outdoor ambient air toxics and risk of breast cancer: The multiethnic cohort

BackgroundA growing literature has reported associations between traffic-related air pollution and breast cancer, however there are fewer investigations into specific ambient agents and any putative risk of breast cancer development, particularly studies occurring in populations residing in higher pollution areas such as Los Angeles. ObjectivesTo estimate breast cancer risks related to ambient air toxics exposure at residential addresses. MethodsWe examined the relationships between ambient air toxics and breast cancer risk in the Multiethnic Cohort among 48,665 California female participants followed for cancer from 2003 through 2013. We obtained exposure data on chemicals acting as endocrine disruptors or mammary gland carcinogens from the National-Scale Air Toxics Assessment. Cox proportional hazards models were used to estimate breast cancer risk per one interquartile range (IQR) increase in air toxics exposure lagged by 5-years. Stratified analyses were conducted by race, ethnicity, and hormone receptor types. ResultsAmong all women, increased risks of invasive breast cancer were observed with toxicants related to industries [1,1,2,2-tetrachloroethane (hazard ratio [HR] = 4.22, 95% confidence interval [95% CI] 3.18–5.60), ethylene dichloride (HR = 2.81, 95% CI 2.20–3.59), and vinyl chloride (HR = 2.27, 95% CI 1.81, 2.85); these 3 agents were correlated (r2 = 0.45–0.77)]. Agents related to gasoline production or combustion were related to increased breast cancer risk [benzene (HR = 1.32, 95% CI 1.24, 1.41), ethylbenzene (HR = 1.20, 95% CI 1.13–1.28), toluene (HR = 1.29, 95% CI 1.20–1.38), naphthalene (HR = 1.11, 95% CI 1.02–2.22), acrolein (HR = 2.26, 95% CI 1.92, 2.65)]. Higher hazard ratios were observed in African Americans and Whites compared to other racial and ethnic groups (p-heterogeneity <0.05 for traffic-related air toxics, acrolein, and vinyl acetate). ConclusionsOur findings suggest that specific toxic air pollutants may be associated with increase breast cancer risk.

Toxic air pollution and concentrated social deprivation are associated with low birthweight and preterm Birth in Louisiana * *K T and G S provide scientific support to communities engaged in environmental advocacy, including litigation, through their work at the Tulane Environmental Law Clinic. They receive no compensation for this work outside of employment. M W declares that she has nothing

Previous studies indicate that pollution exposure can increase risks of adverse birth outcomes, but Black communities are underrepresented in this research, and the potential moderating role of neighborhood context has not been explored. These issues are especially relevant in Louisiana, which has a high proportion of Black residents, an entrenched history of structural racism, the most pounds of toxic industrial emissions annually, and among the nation’s highest rates of low birthweight (LBW), preterm birth (PTB), and infant mortality. We investigated whether air pollution and social polarization by race and income (measured via the index of concentration at the extremes [ICE]) were associated with LBW and PTB among Louisiana census tracts (n = 1101) using spatial lag models. Data sources included 2011–2020 birth records, U.S. Census Bureau 2017 demographic data, and 2017 respiratory hazard (RH) from the U.S. Environmental Protection Agency. Both RH and ICE were associated with LBW (z = 4.4, P < 0.0001; z = −27.0, P < 0.0001) and PTB (z = 2.3, P = 0.019; z = −16.7, P < 0.0001), with no interaction. Severely polluted tracts had 36% higher and 25% higher risks of LBW and PTB, respectively, versus unpolluted tracts. On average, 2166 low birthweight and 3583 preterm births annually were attributable to pollution exposure. Tracts with concentrated social deprivation (i.e. low ICE scores) had 53% higher and 34% higher risks of LBW and PTB, respectively, versus intermediate or mixed tracts. On average, 1171 low birthweight and 1739 preterm births annually were attributable to concentrated deprivation. Our ecological study found that a majority of adverse birth outcomes in Louisiana (i.e. 67% of LBW and PTB combined) are linked to air pollution exposure or disadvantage resulting from social polarization. These findings can inform research, policy, and advocacy to improve health equity in marginalized communities.

The Impact of Lightning NOx Production on Ground‐Level Ozone in Tehran

AbstractLightning‐generated nitrogen oxides (LNOx) have an impact on the concentration of ground‐level ozone which acts as a toxic air pollutant, thereby negatively influencing human health and the environment. To understand the impact of LNOx on ground‐level ozone, we simulated four thunderstorm events in Tehran using the WRF‐Chem model. As observations of LNOx are not available, we evaluated the temporal distribution of the simulated ground‐level ozone concentration against an air quality monitoring station. We also compared the simulation results against the spatial distribution of the total column ozone from the Ozone Monitoring Instrument. WRF‐Chem performs well in the simulation of ground‐level ozone concentration, with the best performance for an event with the highest lightning activity (correlation coefficient of 0.91). The analysis of the spatial distribution of the observed and simulated total column ozone also indicates the good performance of WRF‐Chem. Hourly variation in the simulated LNOx during lightning activity is compared against both hourly variation in the observed ground‐level ozone and the number of lightning for four thunderstorm events. There is an agreement between the simulated LNOx and the observed ground‐level ozone during lightning for two events, with correlation coefficients of 0.55 and 0.57. LNOx emissions enhance ozone production in the middle to upper troposphere, which can subsequently contribute to an increase in ground‐level ozone by transport, vertical mixing, and chemistry. In addition, the initiation of chemical processes in response to cloud‐to‐ground lightning strikes may contribute to an increase in both LNOx and the concentration of ground‐level ozone.

Bio monitoring of toxic pollutants in air and leaves of Ficus religiosa in selected sites of Chennai city

Biomonitoring of vehicle exhaust and deposits of heavy metal on the leaves of the trees located on the roadside was carried out. The selected site Chennai metropolitan city, the capital of Tamil Nadu is a large city, hence divided the city into three sites such as North Chennai, Central Chennai and South Chennai. From these sites, we selected Ficus religiosa trees that are located alongside the roads where a greater number of vehicles pass by. We examined the atmospheric polluted gases by means of using gas sensors and the pollutants on the leaf samples from all the selected sites of Chennai city. For the present study, Ficus religiosa was chosen which belongs to the family Moraceae (the Mulberry family) to know the atmospheric air pollution in our surroundings and the heavy metals (lead, copper, nickel) deposition on the leaves of the trees through Atomic Absorption spectrometry. The ultimate aim of this work is to bio monitor and correlate the existing particulate matter present in the atmosphere and heavy metal deposition in the Ficus religiosa tree leaves of selected sites of Chennai city. The findings could be used for further studies about pollution monitoring and improve the tolerance in future.

The relationship between toxic air pollution, health expenditure, and economic growth in the European Union: fresh evidence from the PMG-ARDL model.

Air pollution is a danger to economies throughout the European Union. Industry, population expansion, a building boom owing to housing and infrastructure development, increasing vehicle traffic, crowded streets, a lack of availability of clean fuel, and ineffective control programs are the primary causes. Toxic air is a double-edged sword for a country's health since it affects just a tiny fraction of Europe's population. The financial burden and healthcare expenses for people rise when health expenditures rise. The present research looks at how dangerous air levels, healthcare costs, and the expansion of the European Union's economy are all connected. The findings are based on data collected over 29years and account for the abovementioned variables. The results of the unit root test have the significant probability values of all variables: health expenditures (HE), gross domestic product (GDP), nitrous oxides (NOX), and carbon dioxides (CO2) emissions at both level and first difference. We used the Johansen, Kao, and Pedroni cointegration tests to test the null hypothesis of no cointegration to see that sample variables had a long-term association. The PMG-ARDL test was used to get these findings. The results confirmed the significant probability values of dependent variables in long- and short-run results that GDP has a positive and significant effect on health expenditure, while NOX and CO2 emissions have a negative and significant impact on (HE), in the European Union. To verify the results, we applied the robustness test, fully modified OLS (FMOLD), and dynamic OLS (DOLS); the robustness test results validated the PMG-ARDL test results. Environmental pollution (CO2, NOX) has a significant and negative impact on healthcare expenditures and a significant effect on GDP (HE) in the EU region. The findings of this research have implications for a wide range of parties, including those who would examine the link between factors in a study meant to improve air quality, distribute health resources, or develop strategies for economic development.

Assessing Air Quality Using Multivariate Statistical Approaches

The purpose of the current study was to evaluate air quality in Dong Thap province, Vietnam. The air quality data was collected during 2019–2020, representing the time of pre- and mid-COVID-19. Twenty-seven air quality samples (in the areas of urban, residential-administrative, hospital-schools, and industry-craft village areas) were used for the evaluation. Air quality was evaluated using national technical regulations on air quality, including QCVN 26:2010/BTNMT and QCVN 05:2013/BTNMT. The difference of mean air quality between the areas was examined using a one-way ANOVA followed by the Duncan test at a significant level of 5%. The relationship between air quality parameters and microclimate factors was tested using Pearson correlation. Principal component analysis (PCA) was utilized to identify critical variables and potential sources of air variation. Cluster analysis (CA) was applied to group similar air quality sites, thus recommending air monitoring site selection. The results show that the air quality in the study area is not polluted. The concentrations of noise, TSP, SO2, and NO2in the mid-COVID-19 pandemic were significantly lower than those in the pre-COVID-19 pandemic due to the social distancing policy. There was a close correlation among air quality parameters, except for air humidity. PCA identified two to four potential sources of air variation, explaining 84.3%, 100%, 100% and 89.7% of the total air quality variance at urban, residential–administrative, hospital-schools, and industry-craft villages, respectively. CA divided the 27 sampling sites into eight groups by the differences, mainly in humidity, wind speed noise, TSP, and CO. Eight sampling sites could be potentially reduced from the current monitoring program for representativeness and cost-effectiveness purposes. All air parameters in the current study are significant for monitoring, and the potential sources of air quality variation are traffic activities, industrial production, craft village activities, and daily life using fuels in residential areas. The results of the current study provide useful information for air quality monitoring and management. Future monitoring programs should include toxic air pollutants in air quality monitoring programs. Doi: 10.28991/CEJ-2024-010-02-012 Full Text: PDF

The Effects of Toxic Air Pollutants and Environmental Health on Public Health in Saudi Arabia

The Effects of Toxic Air Pollutants and Environmental Health on Public Health in Saudi Arabia

Dietary supplementations to mitigate the cardiopulmonary effects of air pollution toxicity: A systematic review of clinical trials.

There is a consistent association between exposure to air pollution and elevated rates of cardiopulmonary illnesses. As public health activities emphasize the paramount need to reduce exposure, it is crucial to examine strategies like the antioxidant diet that could potentially protect individuals who are unavoidably exposed. A systematic search was performed in PubMed/Medline, EMBASE, CENTRAL, and ClinicalTrials.gov up to March 31, 2023, for clinical trials assessing dietary supplements against cardiovascular (blood pressure, heart rate, heart rate variability, brachial artery diameter, flow-mediated dilation, and lipid profile) or pulmonary outcomes (pulmonary function and airway inflammation) attributed to air pollution exposure. After reviewing 4681 records, 18 studies were included. There were contradictory findings on the effects of fish oil and olive oil supplementations on cardiovascular outcomes. Although with limited evidence, fish oil offered protection against pulmonary dysfunction induced by pollutants. Most studies on vitamin C did not find protective cardiovascular effects; however, the combination of vitamin C and E offered protective effects against pulmonary dysfunction but showed conflicting results for cardiovascular outcomes. Other supplements like sulforaphane, L-arginine, n-acetylcysteine, and B vitamins showed potential beneficial effects but need further research due to the limited number of existing trials. Although more research is needed to determine the efficacy and optimal dose of anti-inflammatory and antioxidant dietary supplements against air pollution toxicity, this low-cost preventative strategy has the potential to offer protection against outcomes of air pollution exposure.

A SCREENING OF THE HYDROGEN SULFIDE LEVELS IN PLOIEȘTI CITY, ROMANIA

Oil refineries and petrochemical facilities contribute to the pollution of the environment either air, water, or soil releasing hazardous and toxic air pollutants into the atmosphere. These include nitrogen oxides (NOx), carbon monoxide (CO), hydrogen sulfide (H2S), sulfur dioxide (SO2), and particulate matter (PM), affecting both environment and human health. In the range of air pollutants, hydrogen sulfide is less monitored and reported despite its importance in determining adverse effects. Background H2S concentrations in air were found to range commonly from 0.11 ppb to 0.33 ppb. The concentrations in urban areas can reach 1 ppb (~1.4 g m-3) up to more than 90 ppb (~125 g m-3) near sources of H2S emissions. In Romania, the standard for the air in protected areas for the hydrogen sulfide pollutant provides an admissible concentration, over a maximum interval of 30 minutes, of 15 µg/m³. Everything that exceeds this value is considered harmful to human health. The statistics for the H2S time series recorded in Ploiești City by the mobile laboratory of the Environmental Protection Agency Prahova between 2019 and 2021 with a sampling rate of 30 minutes showed that the mean ranged between 1.51 and 3.74 µg/m³, while the maximum reached 59.36 µg/m³ in the east of Ploiești in 2019. Overall, the highest variance occurred in the East and North parts due to the presence of the concentration peaks. Hydrogen sulfide must be considered on the public health agenda, both from the occupational perspective and for the ambient concentrations near significant H2S sources and in background urban areas. The monitoring infrastructure needs to be improved to allow continuous surveillance to ensure reliable databases that support research regarding the health effects of H2S across the concentrations occurring in the urban environment.

Effect of COVID-19 and Air Pollution on the Risk Factors Attributed to COPD, Cardiovascular, and Respiratory Diseases

Context: A wide range of complications, including chronic respiratory diseases, asthma attacks, cardiovascular diseases (CDs), various cancers (blood, lung, and brain), and even death, can result from air pollution. It is essential to assess the health effects on humans caused by environmental air pollutants and non-communicable diseases (NCDs), including coronavirus disease 2019 (COVID-19). The purpose of this review study was to investigate the synergistic effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and air pollutants on the risk factors for chronic obstructive pulmonary disease (COPD), CDs, and respiratory diseases (RDs). Evidence Acquisition: An extensive literature review was conducted. A total of 1 005 articles were retrieved from sources, including Google Scholar, Springer, PubMed, Web of Science, and Springer databases. In the final stage of the literature review, a significant association between mortality related to COVID-19 and air pollution emissions was identified, contributing to the risk factors associated with CDs and RDs. Results: The result showed that air pollution can have synergistic effects on the transmission of SARS-CoV-2 viruses and has an increasing effect on the incidence of RDs [such as SARS and Middle East respiratory syndrome (MERS)] and CDs. According to the findings, exposure to toxic air pollutants, whether chronic or acute, can have severe effects, including a decrease in airway ciliary function, damage to the mucous membrane, reduced air sac elasticity, decreased lung capacity, and an increased risk of CDs. Conclusions: COVID-19 and air pollutants pose a serious threat to human and animal health. Epidemiological studies have shown that in addition to environmental conditions, individual sensitivity plays a key role in the development of conditions such as COPD, CDs, RDs, cancer, and mortality.

Determination of Nylon 66 Microplastics in the Inhalable Fraction of Particulate Matter Using High-Performance Liquid Chromatography – Tandem Mass Spectrometry (HPLC-MS/MS)

Microplastics (MPs) in the air are one of the major concerns due to their possible health risks. In addition, airborne microplastics act as a carrier for several toxic air pollutants and cause carcinogenic, mutagenic and teratogenic effects. Nylon 66 is one of the most abundant MPs in the microenvironments. In this study, we report an optimized method for the quantification of nylon 66 MPs present in the fine particulate matter (PM2.5) using high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The optimized method exhibited excellent linearity, recovery rates, intraday and interday precision and sensitivity. The optimized method was deployed to carry out a pilot study to measure the mass concentrations of nylon 66 microplastics present in the inhalable fraction of particulate matter collected in a shopping complex. The observed mass concentrations of nylon 66 MPs in this study are in the range from 0.30 ng m−3 to 4.37 ng m−3. This study demonstrates the presence of inhalable fraction of nylon 66 MPs in the indoor environment and their mass concentrations were determined using HPLC-MS/MS.

Characterization of toxic air pollutants in Hong Kong, China: Two-decadal trends and health risk assessments

Exposure to toxic air pollutants (TAPs) is linked to the development of cancer and various chronic health issues. While studies on the ambient characteristics of criteria air pollutants such as particulate matter, nitrogen oxides, and ozone have been extensively conducted, research on TAPs in China remains limited. In particular, there has been a lack of long-term observation studies on the potential health risks associated with ambient TAP concentrations. To address this gap, we characterize the long-term trends (2000–2020) of a wide range of TAPs in Hong Kong using ambient monitoring data derived from a TAP monitoring program that has been in operation since the late 1990s. We analyzed TAPs such as diesel particulate matter (DPM), volatile organic compounds, carbonyl compounds, polycyclic aromatic hydrocarbons, hexavalent chromium, and others. We found that most of the TAPs decreased notably over the last two decades, translating to a reduction in economic loss of over HK$2 billion per year in 2016–2020. However, the current state of TAPs still poses significant health risks. The total TAP concentrations in 2016–2020 exceeded the chronic reference guideline value for noncancer health hazard quotient of 1.0 (1.53). The aggregated inhalation cancer risks in the corresponding period were 562.8 in a million population. We found that the top ten TAPs disproportionately accounted for more than 80% of both health estimators. In contrast to earlier years where DPM dominated the cancer risks, the measured VOCs have grown in importance, and they pose cancer risks as significant as DPM in recent years. Our work identifies several areas in enhancing TAP monitoring, which have implications for expanding the monitoring across the Greater Bay Area for improving air quality management from a health-oriented perspective.