Childhood respiratory allergies and symptoms in highly polluted area of Central Europe

Association between exposure to air pollution and risk of allergic rhinitis: A systematic review and meta-analysis

BACKGROUND

Allergic rhinitis (AR) is one of the most common allergic diseases in the world, and usually persists throughout the activity. Epidemiological studies have shown a positive association between air pollution and allergic rhinitis. However, we could not find any meta-analysis of the risk of air pollutants (PM_2.5, PM₁₀, NO₂, SO₂, O₃ and CO) on the prevalence of AR in people of all ages.

OBJECTIVES

Carry out a meta-analysis on the results of recent studies (up to 2020) to present valid information about exposure to air pollution and risk of prevalence of AR.

METHODS

We systematically searched three databases for studies up to December 17, 2020, including air pollution and AR. Random effect models were conducted to estimate the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). Subgroup analysis, funnel plot, Egger's test, and the trim-and-fill method were also conducted.

RESULTS

Thirty-five studies across 12 countries, including a total of 453,470 participants, were included. The OR per 10 μg/m³ increase of pollutants was 1.13 (1.04-1.22) for PM₁₀ and 1.12 (1.05-1.20) for PM_2.5. The OR per 10 μg/m³ increment of gaseous pollutants were 1.13 (1.07-1.20) for NO₂, 1.13 (1.04-1.22) for SO₂ and 1.07 (1.01-1.12) for O₃. No significant association was observed between CO and AR. Children or adolescents are more sensitive to air pollution than adults. The effects of PM₁₀ and SO₂ were significantly stronger in Europe than Asia. The effects of air pollutants were more significant and higher in developing countries than in developed countries, except for PM₁₀. A significant difference of subgroup test was found between developed and developing countries of NO₂.

CONCLUSION

This meta-analysis showed a positive association between air pollution and the prevalence of allergic rhinitis, and identified geographic area and economic level as the potential modifiers for the association.

The impact of traffic-related air pollution on lung function status and respiratory symptoms among children in Klang Valley, Malaysia

Increasing the range of vehicles on traffic roads in the urban area has led to traffic-related air pollution (TRAP) and is currently becoming the main concern for health, especially among children. The study aimed to determine associations between TRAP and respiratory health, also to identify the main factors that influenced them. A cross-sectional comparative study was carried out among children in high and low traffic areas. Air quality monitoring was conducted in six primary schools. A set of standardized questionnaires was distributed to obtain respondents' exposure history and respiratory health symptoms, while spirometry test was carried out to determine the lung function status. There were associations between TRAP and abnormality of FEV₁% among children. NO₂ was the main predictor that influenced both chest tightness and abnormality of FEV₁%. Children exposed to a high level of traffic-related air pollution have an increased risk of respiratory symptoms and abnormality of lung function.

School neighbourhood and compliance with WHO-recommended annual NO2 guideline: A case study of Greater London

Despite several national and local policies towards cleaner air in England, many schools in London breach the WHO-recommended concentrations of air pollutants such as NO₂ and PM_2.5. This is while, previous studies highlight significant adverse health effects of air pollutants on children's health. In this paper we adopted a Bayesian spatial hierarchical model to investigate factors that affect the odds of schools exceeding the WHO-recommended concentration of NO₂ (i.e., 40 μg/m³ annual mean) in Greater London (UK). We considered a host of variables including schools' characteristics as well as their neighbourhoods' attributes from household, socioeconomic, transport-related, land use, built and natural environment characteristics perspectives. The results indicated that transport-related factors including the number of traffic lights and bus stops in the immediate vicinity of schools, and borough-level bus fuel consumption are determinant factors that increase the likelihood of non-compliance with the WHO guideline. In contrast, distance from roads, river transport, and underground stations, vehicle speed (an indicator of traffic congestion), the proportion of borough-level green space, and the area of green space at schools reduce the likelihood of exceeding the WHO recommended concentration of NO₂. We repeated our analysis under a hypothetical scenario in which the recommended concentration of NO₂ is 35 μg/m³ - instead of 40 μg/m³. Our results underscore the importance of adopting clean fuel technologies on buses, installing green barriers, and reducing motorised traffic around schools in reducing exposure to NO₂ concentrations in proximity to schools. Also, our findings highlight the presence of environmental inequalities in the Greater London area. This study would be useful for local authority decision making with the aim of improving air quality for school-aged children in urban settings.

A review on the role of dispersion and receptor models in asthma research

There is substantial evidence that air pollution exposure is associated with asthma prevalence that affects millions of people worldwide. Air pollutant exposure can be determined using dispersion models and refined with receptor models. Dispersion models offer the advantage of giving spatially distributed outdoor pollutants concentration while the receptor models offer the source apportionment of specific chemical species. However, the use of dispersion and/or receptor models in asthma research requires a multidisciplinary approach, involving experts on air quality and respiratory diseases. Here, we provide a literature review on the role of dispersion and receptor models in air pollution and asthma research, their limitations, gaps and the way forward. We found that the methodologies used to incorporate atmospheric dispersion and receptor models in human health studies may vary considerably, and several of the studies overlook features such as indoor air pollution, model validation and subject pathway between indoor spaces. Studies also show contrasting results of relative risk or odds ratio for a health outcome, even using similar methodologies. Dispersion models are mostly used to estimate air pollution levels outside the subject's home, school or workplace; however, very few studies addressed the subject's routines or indoor/outdoor relationships. Conversely, receptor models are employed in regions where asthma incidence/prevalence is high or where a dispersion model has been previously used for this assessment. Road traffic (vehicle exhaust) and NOx are found to be the most targeted source and pollutant, respectively. Other key findings were the absence of a standard indicator, shortage of studies addressing VOC and UFP, and the shift toward chemical speciation of exposure.

Indoor and Outdoor Pollution as Risk Factor for Allergic Diseases of the Skin and Lungs

Air pollution is worldwide a major public health problem and affects large part of the population. Air pollution does not only harm the respiratory tract system but also the other organs of the body. The damage may result directly from the pollutants toxicity, because the pollutant enters into the organs through a direct route or indirectly through systemic inflammation. There is accumulating evidence suggesting that ambient air pollution not only affects the human lung and the cardiovascular system, but also has negative effects on allergic diseases. In this regard, it has been shown that exposure increases the risk of allergies and eczema in children and adults. However, the mechanism how ambient air pollution affects the skin is not well investigated up to now and needs further research.

Effect of particulate matter exposure on the prevalence of allergic rhinitis in children: A systematic review and meta-analysis

Among various air pollutants, particulate matter (PM) is the most harmful and representative pollutant. At the same time, allergic rhinitis (AR) is getting more and more attention, so we explore the relationship between PM and the prevalence of AR among children. Then, PubMed, Web of Science, Google Scholar was used to search for relevant studies up to January 2020. Literature quality assessment was processed using the Newcastle-Ottawa Scale (NOS) evaluation scale. Adjusted odds ratio (OR) with corresponding 95% confidence interval (CI) was retrieved from individual studies and pooled to generate a summary effect via STATA software. Besides, we test the result stability by Egger's test and funnel plot, and using the trim-and-fill method to modify the possible asymmetric funnel graph. 21 studies were included in the meta-analysis. 9 articles reported about PM_2.5 on childhood AR (1.09, 95%CI: 1.01, 1.17, per 10 μg/m³ increase). 15 articles reported about PM₁₀ on childhood AR (1.06, 95%CI: 1.02,1.11, per 10 μg/m³ increase), PM_2.5 exposure has a bigger effect on children AR than PM₁₀. In addition, a series of subgroup analysis was performed, and we found that PM_2.5 and PM₁₀ have different performances in different subgroups. In addition to this, we analyzed the sources of heterogeneity of the study. Apart from the results we got all have good stability without publication bias. Therefore, it can be concluded that exposure to PM may increase the prevalence of AR among children.

Physiologically-based pharmacokinetic modeling of benzo(a)pyrene and the metabolite in humans of different ages

Age-specific differences in the pharmacokinetics of benzo(a)pyrene (BaP) and its metabolite 3-hydroxybenzo(a)pyrene (3-OHBaP) potentially affect time courses of tissue concentration; however, the quantitative impact of these differences is not well characterized. Our objective was to quantify the effect of age-specific differences in physiological and biochemical parameters on the pharmacokinetics of BaP and 3-OHBaP from newborn at birth to adulthood following inhalation exposure. The time courses of BaP and 3-OHBaP were simulated by using a physiologically based pharmacokinetic model with Advanced Continuous Simulation Language (ACSLX). The concentrations of BaP increased with age in the liver but decreased with age in most tissues, urine, and blood. The concentrations of 3-OHBaP were the highest in the newborns. Our results also showed that the concentration of BaP has almost reached a steady state in the kidney, liver, lung, rapidly perfused tissues, slowly perfused tissues, and skin except for adipose tissues. However, the concentration of 3-OHBaP has reached a steady state in all tissues. This study suggests that age-specific parameters have an effect on the pharmacokinetics of BaP and 3-OHBaP. In particular, tissue concentration in the newborns is higher than other age groups, which indicates that the newborns are susceptible to environmental BaP exposure.

Time Series Analysis of Climate and Air Pollution Factors Associated with Atmospheric Nitrogen Dioxide Concentration in Japan

Nitrogen dioxide (NO₂) is an air pollutant discharged from combustion of human activities. Nitrous acid (HONO), measured as NO₂, is thought to impact respiratory function more than NO₂. HONO and NO₂ have an equilibrium relationship, and their reaction is affected by climate conditions. This study was conducted to discuss the extent of HONO contained in NO₂, depending on the level of urbanization. Whether climate conditions that promote HONO production enhanced the level of NO₂ measured was investigated using time series analysis. Climate and outdoor air pollution data measured in April 2009-March 2017 in urban (Tokyo, Osaka, and Aichi) and rural (Yamanashi) areas in Japan were used for the analysis. Air temperature had a trend of negative associations with NO₂, which might indicate the decomposition of HONO in the equilibrium between HONO and NO₂. The associations of relative humidity with NO₂ did not have consistent trends by prefecture: humidity only in Yamanashi was positively associated with NO₂. In high relative humidity conditions, the equilibrium goes towards HONO production, which was observed in Yamanashi, suggesting the proportion of HONO in NO₂ might be low/high in urban/rural areas.

Deep learning for identifying environmental risk factors of acute respiratory diseases in Beijing, China: implications for population with different age and gender

This study focuses on identifying environmental health risk factors related to acute respiratory diseases using deep learning method. Based on respiratory disease data, air pollution data and meteorological environmental data, cross-domain risk factors of acute respiratory diseases were identified in Beijing, China. We conducted age and gender stratified deep neural network models in air pollution epidemiology. We ranked risk factors of respiratory diseases in stratified populations and conducted quantitative comparison. People ≥50 years were more sensitive to PM_2.5 pollution than <50 years people, especially women ≥50 years. Compared with women, both men ≥50 years and <50 years were more susceptible to PM₁₀. Young women <50 years were more sensitive to general air pollutants such as SO₂ and NO₂ than <50 years young men. Meteorological factors such as wind speed and precipitation could promote the diffusion of fine particulate matter and general air pollutants (SO₂, NO₂, etc.), which could help to reduce the incidence of acute respiratory diseases. This study represents a quantitative analysis of environmental health risk factors identification related to acute respiratory diseases based on deep neural network method. The results of this study could help people to improve their awareness of acute respiratory diseases prevention.

Association between indoor nitrous acid, outdoor nitrogen dioxide, and asthma attacks: results of a pilot study

The association between nitrogen dioxide (NO₂) and asthma has been investigated. However, conventional NO₂ assays measure nitrous acid (HONO) as NO₂. In this pilot epidemiological observational study, we assessed exposure to indoor HONO and some air pollutants in pediatric asthma patients and examined possible association between exposure and asthma symptoms. Indoor HONO and nitric oxide (NO), which are primarily generated by the combustion of certain substances, were significantly associated with asthma attacks in 2010. In 2010, indoor HONO was closely correlated with indoor NO than with outdoor NO₂. Conversely, in 2012, indoor HONO was closely correlated with outdoor NO₂ and NO than with indoor NO₂ and NO. Outdoor NO₂ was significantly associated with asthma attacks in 2012. Our results highlight the need for further epidemiological studies of the association between indoor HONO and asthma symptoms using multivariate analyses to examine the role of NO₂ in asthma symptoms. Abbreviations: CXCL1: the chemokine (C-X-C motif) ligand 1; EP: the entire study period; FP: the first half of study period; HONO: nitrous acid; NO: nitric oxide; NO₂: nitrogen dioxide; OH radical: hydroxyl radical; SP: the second half of study period; TNF-α: tumor necrosis factor-α; US EPA: United States Environmental Protection Agency; WHO: World Health Organization.

Synoptic approach to evaluate the effect of temperature on pediatric respiratory disease-related hospitalization in Seoul, Korea

BACKGROUND

The spatial synoptic classification (SSC) scheme is a daily weather-type classification scheme that is widely used in climatological and epidemiological investigations. We investigated the modification effect of temperature on respiratory disease-related hospital admissions (RAs) in children based on the SSC type.

METHODS

Data on RAs among children aged ≤19 years were collected from the National Inpatient Sample (NIS) database between 2011 and 2015 in Seoul, Korea. In this time-series study, we used Poisson generalized linear models allowing for over-dispersion, with stratification by season and each of the seven distinctive SSC types (Dry moderate [DM], Dry polar [DP], Dry tropical [DT], Moist moderate [MM], Moist polar [MP], Moist tropical [MT], and Transition [T]). We investigated the modification effects of temperature by SSC type through seasonal stratification, adjusting for other meteorological conditions, air pollution, and time trends, and considered the delayed effect for up to four consecutive days. We reported the relative risk percentage change with 95% confidence intervals (CIs) of RAs for every 1 °C increase in ambient temperature, by season and SSC type.

RESULTS

Of the 8346 RAs overall investigated between 2011 and 2015, there were 5271 [63.2%] RAs in children aged 0-4 years. Overall, on majority of the days, the SSC types were DM (665 days [36.4%]), and DP (371 days [20.3%]). With regard to seasons, the different SSC types were distributed as follows: spring, DM (193 days [42.0%]); summer, MT (193 days [42.0%]); fall, DM (241 days [53.0%]); and winter, DP (228 days [50.6%]). A stronger association between RAs and temperature was observed overall (1.28% [95% CI; 0.04%, 2.53%]), and in spring (2.10% [0.62%, 3.60%]). According to SSC type, increased associations between RAs and temperature were detected with DM (2.20% [0.47%, 3.97%]) condition during spring and DT (2.41% [0.22%, 4.64%]) during fall. In addition, on re-categorizing the SSC types from a temperature or humidity standpoint, a modified association was observed especially in children aged ≤4 years and 5-9 years during spring.

CONCLUSIONS

Using temperature variability to distinguish seasonal characteristics, we found that the relationship between temperature and RAs in children varied by SSC type. Application of the SSC scheme as an integrative approach may assist in gaining an understanding of seasonal characteristics and health effects due to temperature change.