Ultrafine particles and black carbon personal exposures in asthmatic and non-asthmatic children at school age

Variability in personal exposure to ultrafine and fine particles by microenvironment among adolescents in Cincinnati

Personal exposure to air pollution is influenced by an individual's time-activity patterns, but data regarding personal exposure to air pollution among children populations is lacking. The objective of this study was to characterize personal exposure to both PM2.5 and ultrafine particles (UFPs) using two portable real-time monitors, combined with GPS logging, and describe the relationship between these exposures across time and microenvironments among adolescents with asthma. Participants completed personal exposure monitoring for seven consecutive days and PM2.5 and UFP concentrations experienced in five microenvironments were determined using GPS location and mobility data. Average UFP and PM2.5 exposure varied across microenvironments with the highest average UFP exposure concentrations observed in transit (10,910 ± 27,297 p/cc), though correlations between UFP and PM2.5 concentrations in transit were low (0.24) and did not reach statistical significance (p > 0.05). We calculated exposure time ratios for each participant. Across participants, UFP exposures within the transit environment demonstrated the highest ratio (average exposure-time ratio = 1.91) though only 3 % of overall sampling time among all participants was monitored in transit (74/2840 h). We did not observe similar trends among PM2.5 exposures. The correlations between UFP and PM2.5 exposures varied throughout the day, with an overall correlation ranging from moderate to high among participants. Identifying microenvironments and activities where high exposure to PM occurs may offer potential targets for interventions to reduce overall exposures among sensitive groups.

Personal exposure to ultrafine particles in multiple microenvironments among adolescents

BACKGROUND

Experimental studies suggest ultrafine particles (UFPs), the smallest size fraction of particulate matter, may be more toxic than larger particles, however personal sampling studies in children are lacking.

OBJECTIVE

The objective of this analysis was to examine individual, housing, and neighborhood characteristics associated with personal UFP concentrations as well as the differences in exposures that occur within varying microenvironments.

METHODS

We measured weekly personal UFP concentrations and GPS coordinates in 117 adolescents ages 13-17 to describe exposures across multiple microenvironments. Individual, home, and neighborhood characteristics were collected by caregiver completed questionnaires.

RESULTS

Participants regularly exposed to secondhand tobacco smoke had significantly higher indoor concentrations of UFPs compared to participants who were not. We observed that the 'home' microenvironment dominated the relative contribution of overall UFP concentrations and sampling time, however, relative proportion of integrated UFP exposure were higher in 'other' environments.

IMPACT STATEMENT

In this study, we employed a novel panel study design, involving real-time measurement of UFP exposure within the multiple microenvironments of adolescents. We found a combination of personal sampling and detailed activity patterns should be used in future studies to accurately describe exposure-behavior relationships.

Investigation of the Exposure of Schoolchildren to Ultrafine Particles (PM0.1) during the COVID-19 Pandemic in a Medium-Sized City in Indonesia

The health risk of schoolchildren who were exposed to airborne fine and ultrafine particles (PM0.1) during the COVID-19 pandemic in the Jambi City (a medium-sized city in Sumatra Island), Indonesia was examined. A questionnaire survey was used to collect information on schoolchildren from selected schools and involved information on personal profiles; living conditions; daily activities and health status. Size-segregated ambient particulate matter (PM) in school environments was collected over a period of 24 h on weekdays and the weekend. The personal exposure of PM of eight selected schoolchildren from five schools was evaluated for a 12-h period during the daytime using a personal air sampler for PM0.1 particles. The schoolchildren spent their time mostly indoors (~88%), while the remaining ~12% was spent in traveling and outdoor activities. The average exposure level was 1.5~7.6 times higher than the outdoor level and it was particularly high for the PM0.1 fraction (4.8~7.6 times). Cooking was shown to be a key parameter that explains such a large increase in the exposure level. The PM0.1 had the largest total respiratory deposition doses (RDDs), particularly during light exercise. The high level of PM0.1 exposure by indoor sources potentially associated with health risks was shown to be important.

Personal Exposure to Black Carbon at School and Levels of Fractional Exhaled Nitric Oxide in New York City

BACKGROUND

Schools are often located near traffic sources, leading to high levels of exposure to traffic-related air pollutants, including black carbon (BC). Thus, the school environment could play in a significant role in the adverse respiratory health of children.

OBJECTIVES

Our objective was to determine associations between personal BC levels at school and airway inflammation [i.e., fractional exhaled nitric oxide (FeNO)] in school-age children. We hypothesized that higher school BC (SBC) would be associated with higher FeNO.

METHODS

Children 9-14 years of age in New York City (NYC) (n=114) wore BC monitors for two 24-h periods over a 6-d sampling period, repeated 6 months later. SBC was defined as the average personal BC concentrations measured during NYC school hours (i.e., 0830-1430 hours). FeNO was measured following each 24-h BC monitoring period. Multivariable linear regression in generalized estimating equation models were used to examine associations between SBC and FeNO. Results are presented as percentage difference (PD) in FeNO.

RESULTS

Personal BC at school was associated with higher FeNO (PD=7.47% higher FeNO per 1-μg/m3 BC (95% CI: 1.31, 13.9), p=0.02]. Compared with BC exposure during school, a smaller PD in FeNO was observed in association with BC exposure while commuting to and from school [PD=6.82% (95% CI: 0.70, 13.3), p=0.03]. Personal BC in non-school environments and residential BC were not associated with FeNO (p>0.05). A significant association between personal BC at school and FeNO was observed among children with seroatopy who did not have asthma [PD=21.5% (95% CI: 4.81, 40.9), p=0.01].

DISCUSSION

Schools may be important sources of BC exposure that contribute to airway inflammation in school-age children. Our results provide rationale for interventions that target improved air quality in urban schools and classrooms. https://doi.org/10.1289/EHP8985.

Characterising professional drivers' exposure to traffic-related air pollution: Evidence for reduction strategies from in-vehicle personal exposure monitoring

Professional drivers working in congested urban areas are required to work near harmful traffic related pollutants for extended periods, representing a significant, but understudied occupational risk. This study collected personal black carbon (BC) exposures for 141 drivers across seven sectors in London. The aim of the study was to assess the magnitude and the primary determinants of their exposure, leading to the formulation of targeted exposure reduction strategies for the occupation. Each participant's personal BC exposures were continuously measured using real-time monitors for 96 h, incorporating four shifts per participant. 'At work' BC exposures (3.1 ± 3.5 µg/m³) were 2.6 times higher compared to when 'not at work' (1.2 ± 0.7 µg/m³). Workers spent 19% of their time 'at work driving', however this activity contributed 36% of total BC exposure, highlighting the disproportionate effect driving had on their daily exposure. Taxi drivers experienced the highest BC exposures due to the time they spent working in congested central London, while emergency services had the lowest. Spikes in exposure were observed while driving and were at times greater than 100 µg/m³. The most significant determinants of drivers' exposures were driving in tunnels, congestion, location, day of week and time of shift. Driving with closed windows significantly reduced exposures and is a simple behaviour change drivers could implement. Our results highlight strategies by which employers and local policy makers can reduce professional drivers' exposure to traffic-related air pollution.

Air quality around schools: Part I - A comprehensive literature review across high-income countries

Children are particularly vulnerable to the detrimental health impacts of poor air quality. In the UK, recent initiatives at local council level have focussed on mitigating children's air pollution exposure at school. However, an overview of the available evidence on concentration and exposure in school environments - and a summary of key knowledge gaps - has so far been lacking. To address this, we conducted a review bringing together recent academic and grey literature, relating to air quality in outdoor school environments - including playgrounds, drop-off zones, and the school commute - across high-income countries. We aimed to critically assess, synthesise, and categorise the available literature, to produce recommendations on future research and mitigating actions. Our searches initially identified 883 articles of interest, which were filtered down in screening and appraisal to a final total of 100 for inclusion. Many of the included studies focussed on nitrogen dioxide (NO₂), and particulate matter (PM) in both the coarse and fine fractions, around schools across a range of countries. Some studies also observed ozone (O₃) and volatile organic compounds (VOCs) outside schools. Our review identified evidence that children can encounter pollution peaks on the school journey, at school gates, and in school playgrounds; that nearby traffic is a key determinant of concentrations outside schools; and that factors relating to planning and urban design - such as the type of playground paving, and amount of surrounding green space - can influence school site concentrations. The review also outlines evidence gaps that can be targeted in future research. These include the need for more personal monitoring studies that distinguish between the exposure that takes place indoors and outdoors at school, and a need for a greater number of studies that conduct before-after evaluation of local interventions designed to mitigate children's exposure, such as green barriers and road closures. Finally, our review also proposes some tangible recommendations for policymakers and local leaders. The creation of clean air zones around schools; greening of school grounds; careful selection of new school sites; promotion of active travel to and from school; avoidance of major roads on the school commute; and scheduling of outdoor learning and play away from peak traffic hours, are all advocated by the evidence collated in this review.

Effect of Air Pollution on Obesity in Children: A Systematic Review and Meta-Analysis

Air pollution exposure has been identified as being associated with childhood obesity. Nevertheless, strong evidence of such an association is still lacking. To analyze whether air pollution exposure affects childhood obesity, we conducted a systematic review and meta-analysis utilizing the PRISMA guidelines. Of 7343 studies identified, eight studies that investigated the effects of air pollutant characteristics, including PM_2.5, PM₁₀, PM_coarse, PM_absorbance, NO_x, and NO₂, on childhood obesity were included. The polled effects showed that air pollution is correlated with a substantially increased risk of childhood obesity. PM_2.5 was found to be associated with a significantly increased risk (6%) of childhood obesity (OR 1.06, 95% CI 1.02–1.10, p = 0.003). In addition, PM₁₀, PM_{2.5absorbance}, and NO₂ appeared to significantly increase the risk of obesity in children (OR 1.07, 95% CI 1.04–1.10, p < 0.00; OR 1.23, 95% CI 1.06–1.43, p = 0.07; and OR 1.10, 95% CI 1.04–1.16, p < 0.001, respectively). PM_coarse and NO_x also showed trends towards being associated with an increased risk of childhood obesity (OR 1.07, 95% CI 0.95–1.20, p = 0.291, and OR 1.00, 95% CI 0.99–1.02, p = 0.571, respectively). Strong evidence was found to support the theory that air pollution exposure is one of the factors that increases the risk of childhood obesity.

Personal exposure to equivalent black carbon in children in Milan, Italy: Time-activity patterns and predictors by season

Air pollution is a global threat to public health, especially when considering susceptible populations, such as children. A better understanding of determinants of exposure could help epidemiologists in refining exposure assessment methods, and policy makers in identifying effective mitigation interventions. Through a participatory approach, 73 and 89 schoolchildren were involved in a two-season personal exposure monitoring campaign of equivalent black carbon (EBC) in Milan, Italy. GPS devices, time-activity diaries and a questionnaire were used to collect personal information. Exposure to EBC was 1.3 ± 1.5 μg/m³ and 3.9 ± 3.3 μg/m³ (mean ± sd) during the warm and the cold season, respectively. The highest peaks of exposure were detected during the home-to-school commute. Children received most of their daily dose at school and home (82%), but the highest dose/time intensity was related to transportation and outdoor environments. Linear mixed-effect models showed that meteorological variables were the most influencing predictors of personal exposure and inhaled dose, especially in the cold season. The total time spent in a car, duration of the home-to-school commute, and smoking habits of parents were important predictors as well. Our findings suggest that seasonality, time-activity and mobility patterns play an important role in explaining exposure patterns. Furthermore, by highlighting the contribution of traffic rush hours, transport-related microenvironments and traffic-related predictors, our study suggests that acting on a local scale could be an effective way of lowering personal exposure to EBC and inhaled dose of children in the city of Milan.

Exposure to ambient air pollution and blood lipids in children and adolescents: A national population based study in China

Few studies have explored the links of air pollution and childhood lipid profiles and dyslipidemias. We aimed to explore this topic in Chinese children and adolescents. This study included 12,814 children aged 7-18 years who participated in a national survey in 2013. Satellite-based spatial-temporal model was used to predict 3-y (2011-2013) average particles with diameters ≤ 1.0 μm (PM₁), ≤2.5 μm (PM_2.5), ≤10 μm (PM₁₀), and nitrogen dioxide (NO₂) concentrations. Generalized linear mixed models were employed to evaluate the relationships of air pollution and total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and dyslipidemias. Every 10 μg/m³ increase in PM₁, PM_2.5, PM₁₀, and NO₂ was related to increases of 6.20% [95% confidence interval (CI): 2.44, 10.10], 5.31% (95%CI: 0.41, 10.44), 3.49% (95%CI: 0.97, 6.08), and 5.25% (95%CI: 1.56, 9.07) in TC, respectively. The odds ratio of hypercholesterolemia associated with a 10 μg/m³ increase in PM₁, PM_2.5, and NO₂ was 2.15 (95%CI: 1.27, 3.65), 1.70 (95%CI: 1.12, 2.60), and 1.43 (95%CI: 1.05, 1.93), respectively. No associations were found for air pollution and other blood lipids. Long-term PM₁, PM_2.5, PM₁₀, and NO₂ exposures were positively associated with TC levels and risk of hypercholesterolemia in children and adolescents.

Personal black carbon and ultrafine particles exposures among high school students in urban China

Air pollution is a major public health challenge in the highly urbanized megacities of China. However, knowledge on exposure to ambient unregulated air pollutants such as black carbon (BC) and ultrafine particles (UFP) among the Chinese population, especially among urban high school students who may have highly variable time-activity patterns, is scarce. To address this, the personal exposures to BC and UFP of high school students (aged 17 to 18) in Chengdu, China were measured at 1-min intervals via portable samplers. Monitoring lasted for 2 consecutive 24-h periods with days classified as "school days" or "non-school days". Time-activity diaries and measurements were combined to explore spatial, temporal, and behavioral factors that contribute to different exposure profiles. The overall geometric means of BC and UFP were 3.60 μg/m³ and 1.83 × 10⁴p/cm³, respectively with notable spatiotemporal variation in exposures observed. In general, the household and transport microenvironments were the predominant contributors to total BC (74.5%) and UFP (36.5%) exposure. However, the outdoor public microenvironment was found to have significantly higher overall average levels of BC than the household and transport microenvironments (p < 0.001) while also presenting the greatest exposure dose intensity (EDI - a measure of exposure in a microenvironment in proportion to time spent in that environment) of 4.79. The largest overall average level of UFP occurred in the indoor public microenvironment followed by transport. The outdoor public microenvironment also presented the greatest EDI of UFP (4.17). This study shows notable spatiotemporal variety in exposure patterns and will inform future exposure and population health studies. The high EDI outdoors may mean that health positive activities, such as exercise, may be being undermined by ambient pollution.

Personal black carbon exposure and its determinants among elderly adults in urban China

Personal exposure to air pollution is affected by its concentration in the microenvironment and individual time-activity patterns. To investigate personal black carbon (BC) exposure levels and identify their potential determinants, we conducted a panel study among 67 elderly residents aged 60-69 years in Jinan, China. Personal BC exposure was measured using portable real-time monitors, while corresponding ambient BC concentrations and meteorological conditions were also collected from the local central site. Time-activity and household characteristics were recorded. A linear mixed-effects model was used to identify potential determinants of personal BC exposure. The daily average personal BC exposure concentration was 4.1 ± 2.0 μg/m³ (±standard deviation, SD), which was significantly lower than the ambient concentration (4.6 ± 2.5 μg/m³) (p < 0.001). Strong correlation (Spearman's r = 0.63, p < 0.001) was found between personal and ambient BC concentrations. The fixed-site monitoring ambient concentration cannot fully reflect the actual personal exposure concentration. Ambient BC concentration, ambient temperature, relative humidity, education level and air purifier use were significant determinants of personal BC exposure. Our findings highlight the need for detailed assessment of personal exposure on health risk assessment of BC and also help develop strategies for targeted risk reduction.

Relationship between indoor and outdoor size-fractionated particulate matter in urban microenvironments: Levels, chemical composition and sources

Exposure to particulate matter (PM) has been associated with adverse health outcomes, particularly in susceptible population groups such as children. This study aims to characterise children's exposure to PM and its chemical constituents. Size-segregated aerosol samples (PM0.25, PM0.25-0.5, PM0.5-1.0, PM1.0-2.5 and PM2.5-10) were collected in the indoor and outdoor of homes and schools located in Lisbon (Portugal). Organic and elemental carbon (OC and EC) were determined by a thermo-optical method, whereas major and trace elements were analysed by X-Ray Fluorescence. In school, the children were exposed to higher PM concentrations than in home, which might be associated not only to the elevated human occupancy but also to outdoor infiltration. The pattern of PM mass size distribution was dependent on the location (home vs. school and indoor vs. outdoor). The presence of EC in PM0.25 and OC in PM0.25-0.5 was linked to traffic exhaust emissions. OC and EC in PM2.5-10 may be explained by their adhesion to the surface of coarser particles. Generally, the concentrations of mineral and marine elements increased with increasing PM size, while for anthropogenic elements happened the opposite. In schools, the concentrations of mineral matter, anthropogenic elements and marine aerosol were higher than in homes. High mineral matter concentrations found in schools were related to the close proximity to busy roads and elevated human occupancy. Overall, the results suggest that exposure to PM is relevant and highlights the need for strategies that provide healthier indoor environments, principally in schools.

Exposure to ultrafine particles in children until 18 years of age: A systematic review

Airborne ultrafine particles (UFP) have been related to adverse health effects, but exposure in vulnerable population groups such as children is still not well understood. We aim to review the scientific literature regarding personal exposure to UFP in different microenvironments in populations until 18 years of age. The bibliographical search was carried out in July 2019 using the online database PubMed and was completed with references in articles found in the search. We selected the studies that used continuous counters and measured UFP levels in both specific microenvironment (houses, schools, transport, etc) and personal exposure. Finally, 32 studies fulfilled the criteria: of these, 10 analyzed personal exposure and 22 examined UFP levels in the microenvironment (especially in schools or nurseries (18/22)) and five in various microenvironments (including dwellings and means of transport, where exposure levels were higher). The characteristics of the microenvironments with the greatest levels of UFP were being close to heavy traffic or near cooking and cleaning activities. This review revealed the wide differences in exposure assessment methodologies that could lead to a lack of uniform and comparable information about the real UFP exposure in children.

Particulate matter air pollution and blood glucose in children and adolescents: A cross-sectional study in China

BACKGROUND

The health effects of particulate matter (PM) air pollution on glucose metabolism have been rarely examined in children and adolescents.

OBJECTIVE

We aimed to investigate the associations between long-term PM exposure and blood glucose and prevalence of impaired fasting glucose in a large population of Chinese children and adolescents.

METHODS

In 2013, a total of 11,814 children and adolescents aged 7 to 18 years were recruited from seven provinces/municipalities in China. Fasting blood sample was taken for the measurement of blood glucose. Satellite-based spatial-temporal models were used to estimate exposure to ambient submicrometer particles (PM₁), fine particles (PM_2.5) and thoracic particles (PM₁₀). Cross-sectional analyses were performed using mixed-effects multivariable linear and logistic regression models.

RESULTS

After adjustment for a range of covariates, every 10 μg/m³ increment in PM₁, PM_2.5 and PM₁₀ concentrations was associated with 0.160 [95% confidence interval (CI): 0.039, 0.280], 0.150 (95% CI: 0.044, 0.256) and 0.079 (95% CI: -0.009, 0.167) mmol/L higher blood glucose levels, respectively. PM exposure was also associated with higher prevalence of impaired fasting glucose, but the associations did not reach statistical significance [odds ratio per 10 μg/m³ increment in PM₁, PM_2.5 and PM₁₀: 1.30 (95% CI: 0.86,1.96), 1.20 (95% CI: 0.85,1.69) and 1.08 (95% CI: 0.83,1.41)].

CONCLUSIONS

We found that long-term exposure to PM air pollution was associated with increased levels of blood glucose in children and adolescents. The associations were more evident for PM₁ and PM_2.5.

Predictors of personal exposure to black carbon among women in southern semi-rural Mozambique

Sub-Saharan Africa (SSA) has the highest proportion of people using unclean fuels for household energy, which can result in products of incomplete combustion that are damaging for health. Black carbon (BC) is a useful marker of inefficient combustion-related particles; however, ambient air quality data and temporal patterns of personal exposure to BC in SSA are scarce. We measured ambient elemental carbon (EC), comparable to BC, and personal exposure to BC in women of childbearing age from a semi-rural area of southern Mozambique. We measured ambient EC over one year (2014-2015) using a high-volume sampler and an off-line thermo-optical-transmission method. We simultaneously measured 5-min resolved 24-h personal BC using a portable MicroAeth (AE51) in 202 women. We used backwards stepwise linear regression to identify predictors of log-transformed 24-h mean and peak (90th percentile) personal BC exposure. We analyzed data from 187 non-smoking women aged 16-46 years. While daily mean ambient EC reached moderate levels (0.9 μg/m³, Standard Deviation, SD: 0.6 μg/m³), daily mean personal BC reached high levels (15 μg/m³, SD: 19 μg/m³). Daily patterns of personal exposure revealed a peak between 6 and 7 pm (>35 μg/m³), attributable to kerosene-based lighting. Key determinants of mean and peak personal exposure to BC were lighting source, kitchen type, ambient EC levels, and temperature. This study highlights the important contribution of lighting sources to personal exposure to combustion particles in populations that lack access to clean household energy.

Associations of black carbon with lung function and airway inflammation in schoolchildren

BACKGROUND

Few studies have investigated the 24-hour respiratory health effects of personal black carbon (BC) and ultrafine particles (UFP) exposure in schoolchildren. The objective of this study was to investigate these associations with the lung function in children 10-years old with and without persistent respiratory symptoms.

METHODS

We conducted a cross-sectional study in 305 children (147 and 158 with and without persistent respiratory symptoms, respectively) from three European birth-cohorts: PARIS (France) and INMA Sabadell and Valencia (Spain). Personal 24-hour measurements of exposure concentrations to BC and UFP were performed by portable devices, before lung function testing. Forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and the fraction of exhaled nitric oxide (FeNO) were determined.

RESULTS

There was no association of UFP with lung function parameters or FeNO whereas the increase in 24-hour BC exposure concentrations was related to a statistically significant decrease in lung function parameters only among children with persistent respiratory symptoms [-96.8 mL (95% Confidence Interval CI: -184.4 to -9.1 mL) in FVC, and -107.2 mL (95% CI: -177.5 to -36.9 mL) in FEV₁ for an inter-quartile range of 1160 ng/m³ exposure increase]. A significant positive association between BC and FeNO was observed only in children with persistent respiratory symptoms with current wheezing and/or medication to improve breathing [FeNO increases with +6.9 ppb (95% CI: 0.7 to 13.1 ppb) with an inter-quartile range BC exposure increase].

CONCLUSION

Children suffering from persistent respiratory symptoms appear to be more vulnerable to BC exposure.

Ambient air pollution and overweight and obesity in school-aged children in Barcelona, Spain

BACKGROUND

Ambient air pollution may increase the risk of overweight and obesity in children. However, available evidence is still scarce and has mainly focused on ambient air pollution exposure occurring at home without considering the school environment. The aim of this study is to assess whether exposure to ambient air pollution at home and school is associated with overweight and obesity in primary school children.

METHODS

We studied 2660 children aged 7-10 years during 2012 in Barcelona. Child weight and height were measured and age- and sex-specific z-scores for body mass index (zBMI) were calculated using the WHO growth reference 2007. Overweight and obesity were defined using the same reference. Land use regression models were used to estimate levels of nitrogen dioxide (NO₂), particulate matter <2.5 μm (PM_2.5), <10 μm (PM₁₀) and coarse (PM_coarse) at home. Outdoor levels of NO₂, PM_2.5, elemental carbon (EC), and ultrafine particles (UFP) were measured in the schoolyard. Multilevel mixed linear and ordered logistic models were used to assess the association between ambient air pollution (continuous per interquartile range (IQR) increase and categorical with tertile cutoffs) and zBMI (continuous and ordinal: normal, overweight, obese), after adjusting for socio-demographic characteristics.

RESULTS

An IQR increase in PM₁₀-home (5.6 μg/m³) was associated with a 10% increase in the odds of being overweight or obese (odds ratio (OR) = 1.10; 95% CI = 1.00, 1.22). Children exposed to the highest tertile of UFP-school (>27,346 particles/cm³) had a 30% higher odds of being overweight or obese (OR = 1.30; 95%CI = 1.03, 1.64) compared to the lowest tertile of UFP exposure. We also observed that exposure to NO₂, PM_2.5 or EC at schools was associated with higher odds of overweight or obese at medium compared to low levels of exposure. Home and school exposures did not show any significant associations with zBMI (except PM_2.5-school comparing tertile 2 vs tertile 1) but were similar in direction.

CONCLUSIONS

This study suggests that exposure to ambient air pollution, especially at school, is associated with childhood risk for overweight and obesity. A cautious interpretation is warranted because associations were not always linear and because school and home air pollution measurements were not directly comparable.

Air pollutants may be environmental risk factors in chronic rhinosinusitis disease progression

BACKGROUND

Little is known about the role of environmental exposures in the pathophysiology of chronic rhinosinusitis (CRS). In this study, we measured the impact of air pollutants (particulate matter 2.5 [PM_2.5 ] and black carbon [BC]) on CRS with nasal polyposis (CRSwNP) and CRS without nasal polyposis (CRSsNP).

METHODS

Spatial modeling from pollutant monitoring sites was used to estimate exposures surrounding residences for patients meeting inclusion criteria (total patients, n = 234; CRSsNP, n = 96; CRSwNP, n = 138). Disease severity outcome measures included modified Lund-Mackay score (LMS), systemic steroids, number of functional endoscopic sinus surgeries (FESS), and 22-item Sino-Nasal Outcome Test (SNOT-22) score. PM_2.5 and BC exposures were correlated with outcome measures.

RESULTS

Mean PM_2.5 and BC findings were not significantly different between CRSwNP and CRSsNP patients or patients with and without asthma. Among those with CRSsNP, PM_2.5 was significantly associated with undergoing FESS. For each unit increase in PM_2.5 , there was a 1.89-fold increased risk in the proportion of CRSsNP patients who required further surgery (p = 0.015). This association was not identified in CRSwNP patients (p = 0.445). BC was also significantly associated with SNOT-22 score in the CRSsNP group. For each 0.1-unit increase in BC, there was a 7.97-unit increase in SNOT-22 (p = 0.008). A similar, although not significant, increase in SNOT-22 was found with increasing BC in the CRSwNP group (p = 0.728).

CONCLUSION

Air pollutants correlate with CRS symptom severity that may be influenced by exposure levels, with a more pronounced impact on CRSsNP patients. This study is the first to demonstrate the possible role of inhalant pollutants in CRS phenotypes, addressing a critical knowledge gap in environmental risk factors for disease progression.