Air Pollution Research Articles

Do attitudes toward air pollution influence climate change perception? Evidence from online customers in China

Abstract The perception of climate change as an abstract and distant concept hinders climate action. Previous studies suggest that individuals may conflate climate change and local air pollution due to misconceptions, as these environmental issues share similar emission sources and mitigation strategies. However, it remains uncertain whether leveraging the public's high perception of air pollution can lead to increased climate change awareness and supportive behaviors. In this study, we surveyed 1,236 Chinese online customers to explore the influence of air pollution perception on climate change perception and willingness to pay (WTP) for supporting climate actions. Structural Equation Modeling (SEM) results revealed that higher air pollution perception, which is connected to an individual's living environment and health status, is significantly associated with higher climate change perception. Despite this link, higher climate change perception does not necessarily translate to higher WTP for climate actions. However, air pollution perception can indirectly increase WTP for climate actions by fostering avoidance behavior intentions. For practical implications, our findings suggest that an emphasis on the co-benefits of climate change mitigation efforts for improving air quality may help lead to greater policy support and understanding. Additionally, promoting individual behavioral changes requires connecting these issues to personal experiences and highlighting tangible benefits such as improved health and well-being.

Criteria air pollutants and HIV-related mortality: Insights from a nationwide case-crossover investigation

The heightened vulnerability of individuals with HIV to environmental stressors is well-recognized, yet the role of air pollution in exacerbating HIV-related mortality remains underexplored. In this nationwide, individual-level case-crossover study conducted from 2013 to 2019, we investigated the association between short-term exposure to criteria air pollutants and HIV-related mortality. Our analysis of 38,510 HIV-related deaths revealed significant associations between exposure to PM2.5, PM10, NO2, and CO and increased mortality risk. The effects of PM2.5 and PM10 persisted for two days, whereas NO2 and CO had immediate, same-day impacts. Vulnerability was heightened in individuals under 65 years, males, those with lower educational attainment, and unmarried individuals. Among causes of death, HIV-related malignant neoplasms exhibited the highest sensitivity to particulate matter. Our findings provide novel insights into the relationship between short-term air pollution exposure and HIV-related mortality, emphasizing the increased susceptibility of this immunocompromised population. The results underscore the need for targeted public health interventions to reduce pollution exposure, particularly for the most at-risk demographic groups. This study contributes to a deeper understanding of environmental health risks faced by individuals living with HIV and informs evidence-based policy recommendations.

Non-Conventional Data for Farming-Related Air Pollution: Contributions to Modelling and Risk Assessment in the Lombardy Region, Italy

Air pollution is one of the most critical global health concerns today. While emissions from industrial activities and combustion processes are the primary threats to air quality, intensive farming activities also contribute significantly, especially through ammonia emissions that promote the formation of secondary pollutants, such as particulate matter. Advancements in air quality research have been achieved by enhancements in emissions characterisation, modelling techniques, and sensor technology, expanding the availability of air pollution data beyond traditional ground sensor observations, which are often lacking in rural agricultural areas. Accordingly, this paper demonstrates the advantages of integrating traditional and non-conventional data to investigate farming-related air pollution through a case study in the Lombardy Region, Northern Italy. The study incorporates an array of data sources, including ground sensors and atmospheric composition model estimates. The concurrent utilisation of these diverse datasets is explored through machine learning modelling, focusing on assessing the influence of agricultural activities on particulate matter distribution patterns. Finally, the reliability of non-conventional air pollution data for health risk assessment applications is also investigated. The paper critically discusses the main findings based on empirical results, highlighting the significance of integrating multiple data sources to complement traditional air quality monitoring while outlining the main limitations in terms of the accuracy and usability of such non-conventional data.

Air quality disparities and respiratory health risks in critically polluted and relatively non-polluted areas: a prospective child health study.

Air pollution, a significant global health concern, notably impacts human well-being. Children, owing to their distinctive physiology and behavior, are particularly susceptible to its adverse effects. This prospective study examines air quality variations and respiratory risks in children residing in critically polluted areas (CPA) compared to relatively non-polluted areas (NPA), utilizing a prospective design to understand the impacts of air pollution on children's respiratory health, including measures like relative risk (RR) and attributable risk (AR). This prospective study tracked 739 students of 5th- 7th grade residing in CPA and NPA for one year, and measured the ambient and indoor air quality levels in both these areas. Throughout the study, based on the observed respiratory symptoms new episodes of upper and lower respiratory tract illnesses were recorded for each child on a weekly basis. Incidence rate, RR and AR for both the illnesses were compared. Statistical analysis was performed with SPSS 26.0. The study observes higher concentration for particulate matter and gaseous pollutants at CPA in comparison to NPA. Children living in CPA exhibited a notably greater weekly occurrence of both upper and lower respiratory tract illnesses compared to those in NPA, with RR of 1.26 (95% CI: 1.16-1.37) and 1.74 (95% CI: 1.34-2.27), respectively. The AR associated with air pollution for upper and lower respiratory tract illnesses among CPA students was found to be 20.7% and 42.7%, respectively. This research underscores the pressing need to address air pollution in critically polluted areas and its profound effects on children's respiratory health. Public health interventions, such as reducing emissions from industries and creating green spaces, should be prioritized. Furthermore, early respiratory health screening in schools within polluted areas could aid in the timely diagnosis and management of respiratory issues in children.

Layered Double Hydroxides as Systems for Capturing Small-Molecule Air Pollutants: A Density Functional Theory Study

Air pollutants are usually formed by easily spreading small molecules, representing a severe problem for human health, especially in urban centers. Despite the efforts to stem their diffusion, many diseases are still associated with exposure to these molecules. The present study focuses on modeling and designing two-dimensional systems called Layered Double Hydroxides (LDHs), which can potentially trap these molecules. For this purpose, a Density Functional Theory (DFT) approach has been used to study the role of the elemental composition of LDHs, the type of counterion, and the ability of these systems to intercalate NO2 and SO2 between the LDH layers. The results demonstrated how the counterion determines the different possible spacing between the layers, modulating the internalization capacity of pollutants and determining the stability degree of the system for a long-lasting effect. The variations in structural properties, the density of states (DOS), and the description of the charge transfer have been reported, thus allowing the investigation of aspects that are difficult to observe from an experimental point of view and, at the same time, providing essential details for the effective development of systems that can counteract the spread of air pollutants.

Moss biomonitoring in areas affected by ashfalls of Shiveluch volcano (Kamchatka).

The moss bag technique was applied on Kamchatka to assess the effect of Shiveluch volcano on the air quality. Moss bags were exposed in settlements located at different distances from the volcano and affected by ashfall to varying degrees. The inductively coupled plasma optical emission spectrometry was used for the determination of the content of Al, Ba, Co, Cd, Cr, Cu, Fe, Mn, P, Pb, Sr, S, V, and Zn in both exposed and unexposed moss samples. Relative accumulation factor revealed enrichment of mosses exposed in the area affected by ashfall with Al, Cr, V, and Zn. Correlation and principal component analysis allowed to identify elements of volcanogenic, geogenic, and anthropogenic origin. Ecological risk values less than 150 indicate low potential ecological risk in the region. Active moss biomonitoring can be considered a cheap and efficient tool for in-depth study of the influence of volcanic activity on air quality on the peninsula.

ALICENET – an Italian network of automated lidar ceilometers for four-dimensional aerosol monitoring: infrastructure, data processing, and applications

Abstract. ​​​​​​​Vertically resolved information on aerosol particles represents a key aspect in many atmospheric studies, including aerosol–climate interactions and aerosol impacts on air quality and human health. This information is primarily derived by lidar active remote sensing, in particular with extensive networks currently in operation worldwide. In Italy, the Institute of Atmospheric Sciences and Climate (ISAC) of the National Research Council (CNR) established the ALICENET network of automated lidar ceilometers (ALCs) in 2015. Since then, ALICENET has grown as a cooperative effort of Italian institutions dealing with atmospheric science and monitoring, and it currently includes instruments run by regional environmental protection agencies, universities, research centres, and private companies. In the current configuration, the network makes use of both single-channel ALCs and dual-channel, polarisation-sensitive-system ALCs (referred to as PLCs). The systems operate in very different environments (urban, coastal, mountainous, and volcanic areas) from northern to southern Italy, thus allowing the continuous monitoring of the aerosol vertical distribution across the country. ALICENET also contributes to the EUMETNET programme E-PROFILE, filling an Italian observational gap compared to other EU member states, which generally run extended ALC networks through national meteorological services. In this work, we present the ALICENET infrastructure and the specifically developed data processing centralised at CNR-ISAC, converting raw instrumental data into quantitative, quality-controlled information on aerosol properties ranging from attenuated backscatter to aerosol mass and vertical stratifications. This setup allows us to get insights into the 4D aerosol field over Italy with applications from near-real-time monitoring to long-term analyses, examples of which are reported in this work. Specific comparisons of the ALICENET products to independent measurements obtained with different techniques, such as particulate matter (PM) concentrations from in situ samplers and aerosol optical depth (AOD) from sun photometers, are also included here, revealing the good performances of the ALICENET algorithms. Overall, ALICENET represents a valuable resource to extend the current aerosol observational capabilities in Italy and in the Mediterranean area, and it contributes to bridging the gap between atmospheric science and its application to specific sectors, among which are air quality, solar energy, and aviation safety.

Chronic Exposure to Bioaerosols in PM2.5 from Garbage Stations Accelerates Vascular Aging via the NF-κB/NLRP3 Pathway.

The fine particulate matter (PM2.5) in air pollution is a critical risk factor influencing human health. Our study included 8144 participants andshowed that the risk of major adverse cardiovascular events increases by 35% (HR, 1.35; 95% CI, 1.14-1.60) for participants with thehighest quartile to PM2.5 exposure as compared to those with lowest quartile. Bioaerosols, as an important environmental exposure in PM2.5, can induce systemic chronic inflammation leading to vascular aging. Thus, the effects of bioaerosols are investigated from household garbage stations in PM2.5 on vascular aging, and the underlying mechanisms are explored. In vivo, chronic exposure to bioaerosols upregulated senescence marker expression levels while causing vascular dysfunction and remodeling. In vitro, bioaerosol exposure induced decreased proliferation, G0/G1 arrest, and impaired migration of human umbilical vein endothelial cells (HUVECs). Furthermore, a single bacterium (AS22a) from the bioaerosol community was isolated and demonstrated that it upregulated inflammatory factors and accelerated cell senescence and vascular aging by activating the NF-κB/NLRP3 signaling pathway, which may serve as a primary mechanism underlying vascular aging induced by bioaerosols in PM2.5. These findings suggest that high levels of bioaerosols in household garbage stations may adversely affect cardiovascular health.

‘Fighting for breath’: Inhabiting uninhabitable places

In 2021, clean-air activists Choked Up put up hacked road signs in the London neighbourhoods of Catford, Brixton and Whitechapel. The signs stated: ‘People of colour are more likely to live in an area with illegal pollution levels’. They also demanded ‘Clean air for all’. The following year, Breathe: 2022 by artist Dryden Goodwin was installed across the borough of Lewisham. Depicting people struggling to breathe, like the road signs, the delicate pencil-drawn images were a way of ‘making the invisible visible’. These interventions highlight both the elevated levels of air pollution in particular locations and the unevenness of its distribution. They also point to how places and bodies are interconnected in the air that ‘we’ breathe. Foregrounding this activism, this article draws on Nirmal Puwar’s conceptualisation of the ‘somatic norm’ whereby particular spaces are (or, rather, become) ‘reserved’ for particular bodies and, concomitantly, the ‘ontological anxiety’ provoked when bodies enter into spaces not meant for them. I extend Puwar’s work on Space Invaders in two ways. First, reading air quality research data through work which has theorised the spatial–bodily relationship, the article explores how the yoking together of spaces and bodies can serve to locate people in places which are not fit for habitation. Second, I draw attention to the highly corporeal and emotional ways in which these interconnections are manifested, and like the visceral registers of ‘ontological anxiety’, I consider what this might tell us about spatialised and bodied power relations. To render the asymmetries in air pollution exposure not only visible but sense-able, the article draws on a mobile, emplaced and embodied methodology of walking and cycling through London. The processes of moving, breathing and leaving put into relief both the deep fleshiness of spatial–bodily interconnections and the palpability of the power dynamics which permeate them.

A novel ventilation method: Experimental measurement and numerical simulation of vertical single-row inclined slit ventilation

Existing ventilation technologies often struggle to balance the limited airflow supply with the demands of indoor ventilation and air circulation in winter. This paper introduces a novel ventilation method, vertical single-row inclined slit ventilation (VSISV), which channels airflow through multiple inclined slits spaced at specific intervals along a vertical supply air duct. By ensuring continuity of the upstream and downstream slit jets, a continuous downward airflow is formed, enhancing both winter ventilation performance and indoor air circulation. The method was experimentally measured, with a focus on comparison to the IJV system. At the same airflow rate, it not only efficiently transports the supply air heat from the upper indoor area to the floor but also exhibits strong horizontal diffusion capability. The RNG turbulence model was selected for numerical simulation, focusing on indoor thermal comfort, air quality, and energy-saving potential. The results indicate that, at the same airflow rate, this method effectively maintains high indoor thermal comfort, directs airflow downward from the ceiling, reduces thermal stratification in the upper zone, achieves a more uniform and elevated indoor temperature, enhances indoor air quality, and demonstrates substantial energy-saving potential. This provides valuable insights for energy conservation, emission reduction, and the optimization in winter building ventilation systems.

Evolution of Reactive Organic Compounds and Their Potential Health Risk in Wildfire Smoke.

Wildfires are an increasing source of emissions into the air, with health effects modulated by the abundance and toxicity of individual species. In this work, we estimate reactive organic compounds (ROC) in western U.S. wildland forest fire smoke using a combination of observations from the 2019 Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) field campaign and predictions from the Community Multiscale Air Quality (CMAQ) model. Standard emission inventory methods capture 40-45% of the estimated ROC mass emitted, with estimates of primary organic aerosol particularly low (5-8×). Downwind, gas-phase species abundances in molar units reflect the production of fragmentation products such as formaldehyde and methanol. Mass-based units emphasize larger compounds, which tend to be unidentified at an individual species level, are less volatile, and are typically not measured in the gas phase. Fire emissions are estimated to total 1250 ± 60 g·C of ROC per kg·C of CO, implying as much carbon is emitted as ROC as is emitted as CO. Particulate ROC has the potential to dominate the cancer and noncancer risk of long-term exposure to inhaled smoke, and better constraining these estimates will require information on the toxicity of particulate ROC from forest fires.

Impacts of PM2.5 exposure near cement facilities on human health and years of life lost: A case study in Brazil

Cement factories significantly contribute to atmospheric pollution by generating fine particulate matter (PM2.5), which can potentially increase the mortality risk. The lack of information on the health impacts of PM2.5 pollution from cement operations in Brazil prompted this investigation. We used corrected PM2.5 measurements from low-cost sensors from March 2021 to October 2022 in Rio Branco do Sul, city in the southern region of the country and home to Latin America's largest cement plant, to assess exposure data. Disability-adjusted life years (DALY) method was applied to estimate the years of life lost (YLL) and cost estimate due to deaths from non-accidental causes, cardiovascular and respiratory diseases. The total YLL attributable to PM2.5 concentration was estimated by calculating the attributable fraction (AF) through relative risk. We also collected PM2.5 using a Harvard impactor to evaluate health risks from toxic metals components. During the study period, the analysis of chemical characterization of PM2.5 showed enrichment factors for most elements and the possible influence of the calcination process facilities on the PM2.5 levels. The mean concentration of PM2.5 exceeded the annual WHO air quality guideline (AQG) level, accounted for 3.5%, 4.7%, and 4.3% of total YLL from all causes, cardiovascular, and respiratory diseases, which corresponded to 0.23 (95% CI: 0.17–0.26), 0.06 (95% CI: 0.05–0.07) and 0.03 (95% CI: 0.01–0.06) years loss in life expectancy, respectively. An indirect health cost attributable to PM2.5 resulted in US$ 1.4 million, equivalent to about 3.5% of the total local annual health costs in Rio Branco do Sul, underscoring the significant financial burden of PM2.5 exposures. The greatest economic loss was found in the male age group of 40–69 years and among those with cardiovascular disease, rather than those with respiratory disease. Despite this, the carcinogenic and non-carcinogenic risks from inhalation of hazardous elements were within safe ranges. This work demonstrated PurpleAir's potential for air quality and public health applications. Our findings indicate health and economic benefits from reducing PM2.5 levels by adopting WHO air pollution standards. The results can guide policies toward delivering more effective health care.

Modelling the properties of aerated concrete on the basis of raw materials and ash-and-slag wastes using machine learning paradigm

The thermal power industry, as a major consumer of hard coal, significantly contributes to harmful emissions, affecting both air quality and soil health during the operation and transportation of ash and slag waste. This study presents the modeling of aerated concrete using local raw materials and ash-and-slag waste in seismic areas through machine learning techniques. A comprehensive literature review and comparative analysis of normative documentation underscore the relevance and feasibility of employing non-autoclaved aerated concrete blocks in such regions. Machine learning methods are particularly effective for disjointed datasets, with neural networks demonstrating superior performance in modeling complex relationships for predicting concrete strength and density. The results reveal that neural networks, especially those with Bayesian Regularisation, consistently outperformed decision trees, achieving higher regression values (Rstrength = 0.9587 and Rdensity = 0.91997) and lower error metrics (MSE, RMSE, RIE, MAE). This indicates their advanced capability to capture intricate non-linear patterns. The study concludes that artificial neural networks are a robust tool for predicting concrete properties, crucial for producing non-autoclaved curing wall blocks suitable for earthquake-resistant construction. Future research should focus on optimizing the balance between density and strength of blocks by enhancing the properties of aerated concrete and utilizing reliable models.

A review of environmental and health effects of synthetic cosmetics

The use of cosmetic products is expanding globally, and with it, so is the range of chemical substances employed in their production. As a result, there is also a higher risk of intoxication, allergic reactions, prolonged chemical exposure, adverse effects, and indiscriminate use. Cosmetic products can contain more than 10,000 ingredients. Most users of synthetic cosmetics are unaware of the harmful effects if they even are. However, it is linked to many diseases like cancer, congenital disabilities, reproductive impairments, developmental systems, contact dermatitis, hair loss, lung damage, old age, skin diseases and reactions, allergies, and harm to human nails. Many beauty products also create a high demand for natural oils, leading to extensive and intensive cultivation, harming natural habitats through deforestation, and contaminating soil and water through pesticides and fertilizers. The adverse effects of hazardous substances in synthetic cosmetics extend beyond human health and influence ecosystems, air quality, and oceans. Thus, this review aims to assess the environmental and health impacts of cosmetics using published scientific articles. The study used a systematic review based on Scopus, Science Direct, Web databases, Scholar Google, and PubMed. The results of this review showed that the formulation of cosmetics until the disposal of their containers could adversely affect environmental and human health.

Individual and combined effects of sodium dichloroisocyanurate and isothiazolinone on the cyanobacteria-Vallisneria natans-microbe aquatic ecosystem

The use of algaecides to control high-density cyanobacterial blooms is often complicated by secondary pollution and the toxicity to non-target organisms. This study investigates the individual and combined effects of sodium dichloroisocyanurate (NaDCC, 5, 50, and 100 mg/L) and isothiazolinone (0.1, 0.5, and 1.5 mg/L) on a cyanobacteria-Vallisneria natans-microbe aquatic ecosystem, focusing on their interactions and ecological impacts. Results indicate that NaDCC could achieve a higher algae removal rate than isothiazolinone within 15 days, but has a greater negative effect on Vallisneria natans. Both algaecides disrupt nutrient and secondary metabolite balances at low and high concentrations, increasing nutrient loads and harmful substances. Optimal results were obtained with low concentrations of NaDCC (5 mg/L) and isothiazolinone (0.1 mg/L), effectively controlling cyanobacteria while minimizing harm to Vallisneria natans and reducing nutrient loads and microcystin accumulation. Algaecide application enhanced microbial diversity in water and leaves, shifting the dominant community from cyanobacteria to organisms adapted to the post-cyanobacterial decay environment. Metabolomic analysis indicated increased secretion of lipids and organic acids by cyanobacteria in response to algaecide stress. High concentrations of NaDCC and isothiazolinone disrupted nitrogen metabolism in cyanobacteria and induced ROS overproduction, affecting unsaturated fatty acid synthesis and other metabolic pathways. These findings highlight the importance of exploring different combinations of algaecides to reduce their concentrations, balance algal control with ecological stability, and offer insights for effective eutrophication management.

ТРАНСПОРТНЫЕ КОРИДОРЫ ЦЕНТРАЛЬНОЙ АЗИИ В СОЦИАЛЬНО-ЭКОЛОГИЧЕСКОМ ИЗМЕРЕНИИ

The article examines the socio-ecological aspects of creating transport corridors in Central Asia in the modern context. The region's unique geographical position has long attracted attention, becoming a key link between East and West, particularly along the historical Silk Road. In this regard, the environmental optimization of transport corridors is crucial for sustainable regional development. However, the increase in freight traffic amplifies human impact on the environment, leading to air, water, and soil pollution, as well as changes in the soil's chemical composition and microflora. The article offers recommendations to minimize the negative effects of multimodal transport corridors on the region’s ecosystem, a necessary step toward balancing economic growth with environmental preservation.

Development of modified MgO/biochar composite for chemical adsorption enhancement to cleanup fluoride-contaminated groundwater

Fluoride contamination in groundwater has become a global environmental issue. Magnesium oxide (MgO) has demonstrated effectiveness as an adsorbent in treating fluoride pollution in groundwater. However, its use in powder and fine granular form often results in losses during the adsorption process, posing challenges for post-treatment recovery and potentially causing secondary environmental pollution. In this study, two novel fluoride adsorbents [rice husk (RH) and spent coffee grounds (SCG)-based magnesium oxide (MgO) biochar composites (MgO/RH and MgO/SCG)] were developed to cleanup fluoride-polluted groundwater. During the adsorbent synthesis process, RH and SCG biochar were pyrolyzed at 500 °C and modified by calcination using MgO. Both MgO/RH and MgO/SCG surfaces exhibited abundant pore structures and formed MgO crystal phases. Batch experiments results show that when the MgO/RH and MgO/SCG material dosages were 1 g/L, fluoride removal rates reached 80% and 86% respectively. The isotherms and kinetics of fluoride adsorption with MgO/RH and MgO/SCG followed the Langmuir isotherm equation and pseudo-second-order kinetic model. The maximum fluoride adsorption capacities of MgO/RH and MgO/SCG were 63.47 mg/g and 141.98 mg/g, respectively, indicating these materials used mono-layer adsorption mechanism for fluoride adsorption. The addition of MgO into the pores of porous adsorbent materials effectively increased their reactive sites and enhanced the adsorption performance of carbon materials. Particularly, SCG biochar had a richer pore structure than RH biochar, providing a larger contact surface area, facilitating the effective dispersion and doping of MgO into the pores. Therefore, MgO/SCG composite exhibited excellent fluoride adsorption properties in water, indicating the potential for developing a new type of MgO-modified SCG adsorbent material with green prospects. This composite effectively mitigated fluoride contamination, reducing the fluoride concentration in groundwater. Both RH and SCG are agricultural and food waste by-products, thus offering the opportunity to significantly reduce production, operation, and maintenance costs.

Antibiotic resistance and resistome risks of inhalable bioaerosols at aeration tank of a full-scale wastewater treatment plant

Antibiotic resistome could be aerosolized under wastewater aeration processes, however, their seasonal variation, mobility, hosts, aerosolization behavior, and risk, are largely unknown. Herein, the antibiotic resistant pollution associated with fine particulate matter (PM2.5) from the actual aeration tank (AerT), was analyzed using metagenomic assembly. The antibiotic resistance of AerT-PM2.5 was characterized by significant seasonality. Antibiotic resistance genes (ARGs) in AerT-PM2.5, exhibited higher enrichment and mobility and were harbored more by pathogens than those in upwind-PM2.5, regardless of sampling season. Mobile ARGs were mainly flanked by transposase. Totally, 18 pathogenic antibiotic-resistant bacteria (PARB) carried more than one ARG, including 9 PARB with multiple ARG types. Although wastewater exerted a dominant source contribution for the airborne ARGs (47.31–55.56 %) and PARB (46.18–64.32 %), aeration endowed differential aerosolization capacity for various ARGs and PARB from wastewater. Airborne antibiotic resistome was mainly determined by bacterial community and indirectly influenced by meteorological conditions (i.e., relative humidity). Higher PM2.5-borne resistome risk was observed in AerT than upwind, and the most serious resistome risk of AerT-PM2.5 was found in winter. This study emphasizes the importance of wastewater aeration processes in emission of airborne antibiotic resistome and offers referenced information for mitigating air pollution in wastewater treatment plants.

Environmental house calls can reduce symptoms of chemical intolerance: a demonstration of personalized exposure medicine.

The goals of this investigation were to 1) identify and measure exposures inside homes of individuals with chemical intolerance (CI), 2) provide guidance for reducing these exposures, and 3) determine whether our environmental house calls (EHCs) intervention could reduce both symptoms and measured levels of indoor air contaminants. CI is an international public health and clinical concern, but few resources are available to address patients' often disabling symptoms. Numerous studies show that levels of indoor air pollutants can be two to five (or more) times higher than outdoor levels. Fragranced consumer products, including cleaning supplies, air fresheners, and personal care products, are symptom triggers commonly reported by susceptible individuals. A team of professionals trained and led by a physician/industrial hygienist and a certified indoor air quality specialist conducted a series of 5 structured EHCs in 37 homes of patients reporting CI. We report three case studies demonstrating that an appropriately structured home intervention can teach occupants how to reduce indoor air exposures and associated symptoms. Symptom improvement, documented using the Quick Environmental Exposure and Sensitivity Inventory Symptom Star, corresponded with the reduction of indoor air volatile organic compounds, most notably fragrances. These results provide a deeper dive into 3 of the 37 cases described previously in Perales et al. (2022). We address the long-standing dilemma that worldwide reports of fragrance sensitivity have not previously been confirmed by human or animal challenge studies. Our ancient immune systems' 'first responders', mast cells, which evolved 500 million years ago, can be sensitized by synthetic organic chemicals whose production and use havegrown exponentially since World War II. We propose that these chemicals, which include now-ubiquitous fragrances, trigger mast cell degranulation and inflammatory mediator release in the olfactory-limbic tract, thus altering cerebral blood flow and impairing mood, memory, and concentration (often referred to as 'brain fog'). The time has come to translate these research findings into clinical and public health practice.

Assessment of vehicle exhaust PM emissions using high-resolution on-road measurements in Seoul, Korea

In megacities, road traffic is a major source of particulate matter (PM), requiring a critical understanding of effective air pollution control. Despite existing methods to determine PM emission factors (EFs) of vehicles, accurate estimation of PM emissions under real driving conditions remains challenging. We aimed to assess the EFs of organic aerosol (OA) and equivalent black carbon (eBC) from vehicles through on-road measurements in Seoul, Korea, to understand real-world PM emissions. We used a mobile laboratory equipped with an aerosol mass spectrometer and an aethalometer to measure the composition of PM. On-road measurements were conducted in vehicle tunnels, urban roadways, and residential areas, and the characteristics of measurement points were compared and analyzed. Our results showed that concentrations of OA increased proportionally with the influence of vehicle exhaust, while oxidation states of the OA decreased. Mobile measurements revealed spatial heterogeneities in aerosols, highlighting distinct characteristics of fresh OA on vehicle roads and elevated oxidation state values in residential areas. Active nitrate formation near vehicles led to elevated NO3 concentrations on roads compared to residential areas. Our study shows that mobile PM measurements, including OA and eBC, are valuable for the direct evaluation of emission inventories. However, given that the calculated EFs may not be applicable to other cities due to differences in vehicle composition and traffic conditions, the development of city-specific EFs will be necessary in the future. Furthermore, it is recommended to integrate this methodology with conventional emission inventories to identify vehicle-type-specific emissions.Graphical