Corrigendum to "Relationship between growth and food avoidance with food allergy at age 3 years: The Japan Environment and Children's Study (JECS)" [World Allergy Organ J (2023) 100826].

[This corrects the article DOI: 10.1016/j.waojou.2023.100826.].

Relationship between growth and food avoidance with food allergy at age 3 years: The Japan Environment and Children's Study (JECS).

Background: Basic management for food allergy (FA) is eliminating causative food from the diet, which can impact normal growth. This study examined the association between food avoidance and growth failure among children with FA aged 0-3 years using the Japan Environment and Children's Study (JECS) data. Methods: Data on height, weight, and FA history registered were collected using self-administered questionnaires at age 1, 1.5, 2, and 3 years. A general linear model was used to examine whether dietary restriction affected body size. Height, weight, and body mass index (BMI) were adjusted for age in months using standard deviation (SD) scores for each age group by month of measurement. Presence of FA or dietary restriction was used as a binary variable. Results: Of the 38 477 participants included in this analysis, 4070 with FAs had significantly lower SD scores for height and weight at age 3 years. With milk avoidance, significantly lower SD scores for height (male: ß = -0.097 [95%CI: 0.175, -0.019], female: ß = -0.103 [95%CI: 0.204, -0.002]), a significantly lower SD score for weight (male: ß = -0.115[95%CI: 0.187, -0.043], female ß = -0.114[95%CI: 0.203, -0.026]) were observed. Soy avoidance in males marked a lower SD score for height (ß = -0.307 [95%CI: 0.474, -0.140]). Continued food avoidance until age 3 resulted in significantly lower SD score for height and weight regardless of gender. Conclusion: Growth impairment was observed with food avoidance at age 3 years. Growth impairment were more obvious in males than in females. With regards food items, the impact of milk and soy was more significant.

Association between maternal use of spray formulations and offspring urological anomalies: The Japan Environment and Children's Study.

OBJECTIVE: Concerns exist regarding the effects of maternal inhalation of household products on fetal health. This study aimed to clarify the impact of maternal exposure to household products, including spray formulations, on urological anomalies in offspring up to the age of 1 year. METHODS: This study included data from 84 237 children from the Japan Environment and Children's Study, an ongoing nationwide cohort study. Using maternal self-report questionnaires, information on the use of organic solvents, waterproof sprays, insect-repellent sprays, insecticide sprays, and herbicides from implantation until the second or third trimester of pregnancy and data on urological anomalies were collected 1 year after delivery. RESULTS: Urological anomalies occurred in 799 infants. Multivariate logistic regression analysis adjusted for maternal age, pregnancy body mass index, gestational diabetes, pre-existing maternal kidney disease, and preterm birth revealed no association between maternal exposure to organic solvents and the prevalence of offspring urological anomalies. Nevertheless, we observed significant associations between waterproof spray use during pregnancy and urological anomalies in boys (odds ratio [OR]: 1.28, 95% confidence interval [CI]: 1.03-1.59) and between the use of insecticide spray during pregnancy and urological anomalies in girls (OR: 1.48, 95% CI: 0.98-2.22). Sub-analysis revealed significant associations between waterproof spray use during pregnancy and vesicoureteral reflux in boys (OR: 2.14, 95% CI: 1.02-4.49) and between the use of insecticide spray during pregnancy and hydronephrosis in girls (OR: 2.23, 95% CI: 1.11-4.47). CONCLUSION: Spray formulation use during pregnancy might increase the risk of urological anomalies in the offspring.

Association of epidural analgesia during labor with neurodevelopment of children during the first three years: the Japan Environment and Children's Study.

BACKGROUND: Epidural analgesia relives pain during labor. However, the long-term effects on neurodevelopment in children remain unclear. We explored associations between exposure to epidural analgesia during labor and childhood neurodevelopment during the first 3 years of life, in the Japan Environment and Children's Study (JECS), a large-scale birth cohort study. METHODS: Pregnant women were recruited between January 2011 and March 2014, and 100,304 live births of singleton children born at full-term by vaginal delivery, and without congenital diseases were analyzed. Data on mothers and children were collected using a self-administered questionnaires and medical record transcripts. The children's neurodevelopment was repeatedly assessed for five domains (communication, gross motor, fine motor, problem solving, and personal-social), using the Ages and Stages Questionnaires, Third Edition, at six time points from age 6 to 36 months. After adjusting for potential confounders, the associations between exposure to epidural analgesia during labor and children's neurodevelopment at each time point were assessed. RESULTS: Of the 42,172 children with valid data at all six time points, 938 (2.4%) were born to mothers who received epidural analgesia during labor. Maternal exposure to epidural analgesia was associated with neurodevelopmental delays during the first 3 years after birth. Delay risks in gross and fine motor domains were the greatest at 18 months (adjusted odds ratio (aOR) [95% confidence interval (CI)]: 1.40 [1.06, 1.84] and 1.54 [1.17, 2.03], respectively), subsequently decreasing. Delay risks in communication and problem-solving domains were significantly high at 6 and 24 months, and remained significant at 36 months (aOR [95% CI]: 1.40 [1.04, 1.90] and 1.28 [1.01, 1.61], respectively). Exposure to epidural analgesia was also associated with the incidence of problem solving and personal-social delays from 18 to 24 months old. Neurodevelopmental delay risks, except for communication, were dominant in children born to mothers aged ≥30 years at delivery. CONCLUSIONS: This study showed that maternal exposure to epidural analgesia during labor was associated with neurodevelopmental delays in children during the first 3 years after birth.

Effects of Screen Viewing Time on Sleep Duration and Bedtime in Children Aged 1 and 3 Years: Japan Environment and Children's Study.

This study aimed to clarify the effects of television/digital versatile disc (TV/DVD) viewing time and portable electronic device (PED) usage time on sleep duration and bedtime and the difference between the effects of TV/DVD and PED on sleep. The effect of TV/DVD viewing time or PED usage time on sleep duration and bedtime was analyzed using a multiple logistic regression analysis adjusted for covariates. A total of 74,525 participants were included in the analysis, using data from Japan Environment and Children's Study. TV/DVD viewing was not associated with short sleep duration, but PED usage was associated with short sleep duration. In addition, the risk of short sleep duration increased as PED usage time increased. We also investigated the effects of sleep habits at age 1 year on sleep at age 3 years. This study showed that late bedtime at age 1 year posed a significant risk of late bedtime at age 3 years. In summary, particular caution should be paid to PED use from a child's health perspective, and sleep habits should be focused on bedtime from the age of 1 year.

Early Developmental Signs in Children with Autism Spectrum Disorder: Results from the Japan Environment and Children's Study.

Autism spectrum disorder (ASD) is a developmental disability in early childhood. Early identification and intervention in children with ASD are essential for children and their families. This study aimed to identify the earliest signs of ASD. Using a large cohort including data from 104,062 fetal records in the Japan Environment and Children's Study, we examined the Ages and Stages Questionnaires® (ASQ-3TM) scores of children with and without ASD. The ASQ-3 comprises five domains: communication, gross motor, fine motor, problem solving, and personal-social. The ASQ-3 scores were obtained at ages 6 months, 1 year, and 3 years. There were 64,501 children with available ASQ-3 data. The number of children diagnosed with ASD was 188 (0.29%) at 3 years of age. The highest relative risk (RR) for any domain below the monitoring score at 6 months was in the communication (RR 1.90, 95% CI 1.29-2.78, p = 0.0041), followed by fine motor (RR 1.50, 95% CI 1.28-1.76, p < 0.0001) domain. A low ASQ-3 score in the communication domain at 6 months was related to an ASD diagnosis at 3 years of age. The ASQ-3 score at 6 months can contribute to the early identification of and intervention for ASD.

Association between maternal insecticide use and otitis media in one-year-old children in the Japan Environment and Children's Study.

Otitis media (OM) is common among young children and is related to hearing loss. We investigated the association between maternal insecticide use, from conception to the first and second/third trimesters, and OM events in children in the first year of age. Data from Japan Environment and Children's Study were used in this prospective cohort study. Characteristics of patients with and without history of OM during the first year of age were compared. The association between history of OM in the first year and insecticide use was evaluated using logistic regression analysis. The study enrolled 98,255 infants. There was no significant difference in the frequency of insecticide use between groups. Insecticide use of more than once a week from conception to the first trimester significantly increased the occurrence of OM in children in the first year (odds ratio [OR] = 1.30, 95% confidence interval [CI] 1.01-1.67). The association between OM in the first year and insecticide use from conception to the first trimester was only significant in the group without daycare attendance (OR 1.76, 95% CI 1.30-2.38). Maternal insecticide use more than once a week from conception to the first trimester significantly increased OM risk in offspring without daycare attendance.

Effects of early-life exposure to dust mite allergen and endotoxin on the development of asthma and wheezing: The Japan Environment and Children's Study.

BACKGROUND: The effects of early-life exposure to house dust mite allergen and endotoxin on the development of asthma are unclear in the literature. We investigated the association of early-life exposure (0-36 months old) to house dust mite allergen and endotoxin with asthma incidence. METHODS: In this novel, large-scale, nationwide birth cohort study, 5017 participants were randomly selected from those who met the eligibility criteria. House dust was vacuum-sampled from the children's mattresses within homes and assayed for the presence of dust mite allergen (Der 1) and endotoxin. The participants were classified into four quartiles (Q1-Q4) according to exposure levels. We defined the incidence of asthma and wheezing using questionnaires at 12, 24, and 36 months old. Odds ratios (ORs) of the incidence of asthma and wheezing by age in Der 1 and endotoxin exposure level were estimated using logistic regression. RESULTS: The cumulative incidence rates of asthma and wheezing during 0-36 months were 10.4% and 38.1%, respectively. Significant ORs were observed in asthma onset during 12-24 months old, asthma onset during 24-36 months old, and wheezing onset during 0-12 months old in the Q4 Der 1 group. In the Q4 endotoxin group, significant positive associations between endotoxin exposure and asthma (OR 2.00, 95% confidence interval [CI]: 1.03-3.85) and wheezing (OR 1.78, 95% CI: 1.01-3.12) onset during 24-36 months old were found. CONCLUSIONS: Our results indicated that high levels of early-life exposure to Der 1 and endotoxin in mattresses may be involved in the development of asthma.

Respiratory function declines in children with asthma associated with chemical species of fine particulate matter (PM2.5) in Nagasaki, Japan.

BACKGROUND: The differential effects of PM2.5 fractions on children's lung function remain inconclusive. This study aimed to examine whether lung function in asthmatic children was associated with increased PM2.5 fractions in urban areas in Nagasaki prefecture, Japan, where the air pollution level is relatively low but influenced by transboundary air pollution. METHODS: We conducted a multiyear panel study of 73 asthmatic children (boys, 60.3%; mean age, 8.2 years) spanning spring 2014-2016 in two cities. We collected self-measured peak expiratory flow (PEF) twice a day and daily time-series data for PM2.5 total mass and its chemical species. We fitted a linear mixed effects model to examine short-term associations between PEF and PM2.5, adjusting for individual and time-varying confounders. A generalized linear mixed effects model was also used to estimate the association for worsening asthma defined by severe PEF decline. Back-trajectory and cluster analyses were used to investigate the long-range transboundary PM2.5 in the study areas. RESULTS: We found that morning PEFs were adversely associated with higher levels of sulfate (- 1.61 L/min; 95% CI: - 3.07, - 0.15) in Nagasaki city and organic carbon (OC) (- 1.02 L/min; 95% CI: - 1.94, - 0.09) in Isahaya city, per interquartile range (IQR) increase at lag1. In addition, we observed consistent findings for worsening asthma, with higher odds of severe PEF decline in the morning for sulfate (odds ratio (OR) = 2.31; 95% CI: 1.12, 4.77) and ammonium (OR = 1.73; 95% CI: 1.06, 2.84) in Nagasaki city and OC (OR = 1.51; 95% CI: 1.06, 2.15) in Isahaya city, per IQR increase at lag1. The significant chemical species were higher on days that could be largely attributed to the path of Northeast China origin (for sulfate and ammonium) or both the same path and local sources (for OC) than by other clusters. CONCLUSIONS: This study provides evidence of the differential effects of PM2.5 fractions on lung function among asthmatic children in urban areas, where the Japanese national standards of air quality have been nearly met. Continuous efforts to promote mitigation actions and public awareness of hazardous transboundary air pollution are needed to protect susceptible children with asthma.

Estimating monthly concentrations of ambient key air pollutants in Japan during 2010-2015 for a national-scale birth cohort.

Exposure to ambient air pollution is associated with maternal and child health. Some air pollutants exhibit similar behavior in the atmosphere, and some interact with each other; thus, comprehensive assessments of individual air pollutants are required. In this study, we developed national-scale monthly models for six air pollutants (NO, NO2, SO2, O3, PM2.5, and suspended particulate matter (SPM)) to obtain accurate estimates of pollutant concentrations at 1 km × 1 km resolution from 2010 through 2015 for application to the Japan Environment and Children's Study (JECS), which is a large-scale birth cohort study. We developed our models in the land use regression framework using random forests in conjunction with kriging. We evaluated the model performance via 5-fold location-based cross-validation. We successfully predicted monthly NO (r2 = 0.65), NO2 (r2 = 0.84), O3 (r2 = 0.86), PM2.5 (r2 = 0.79), and SPM (r2 = 0.64) concentrations. For SO2, a satisfactory model could not be developed (r2 = 0.45) because of the low SO2 concentrations in Japan. The performance of our models is comparable to those reported in previous studies at similar temporal and spatial scales. The model predictions in conjunction with the JECS will reveal the critical windows of prenatal and infancy exposure to ambient air pollutants, thus contributing to the development of environmental policies on air pollution.

Association between house renovation during pregnancy and wheezing in the first year of life: The Japan environment and children's study.

BACKGROUND: Wheezing is a common symptom in infants, which may occasionally develop into asthma. There are many factors related to infant wheezing, including anatomical features, viral infections, and passive smoking. There are only a few reports on the association between renovation and pregnancy worldwide, and reports on this association are inadequate in Japan. This study aimed to examine the association between house renovation and new construction during pregnancy and wheezing in infants during the first year of life using data from the Japan Environment and Children's Study (JECS). METHODS: Data of pregnant women registered in JECS were collected using self-administered questionnaires during the second/third trimester and 1 month after delivery. Childbirth records were completed by the doctors. Similarly, wheezing in infants was evaluated using self-administered questionnaires 1 year after birth. Logistic regression analysis was used to determine the primary outcome. RESULTS: In total, 75,731 infants, excluding those with unknown gender, who were not singleton infants, and who relocated during pregnancy and the first month of life, were examined in this study. Renovation during pregnancy increased the prevalence of wheezing (odds ratio [OR]: 1.33, 95% confidence interval [CI]: 1.20-1.48) and recurrent wheezing (OR: 1.22, 95% CI: 1.00-1.48) in the first year of life. The relationship between new construction during pregnancy and wheezing in infants was insignificant (OR: 0.98, 95% CI: 0.90-1.06). CONCLUSIONS: Renovation during pregnancy may be a risk factor for wheezing in infants, and should be avoided.

Effect of Asian dust on respiratory symptoms among children with and without asthma, and their sensitivity.

There has been little study on the effect of Asian dust exposure on respiratory symptoms among children who are vulnerable to environmental factors. In this panel study, we investigated the effect of Asian dust on respiratory symptoms among children with and without asthma, and their sensitivity. Children attending two elementary schools (137 total), and 23 children with asthma from cooperating medical institutions in Fukuoka prefecture were recruited. Subjects measured peak expiratory flow rate (PEF), and recorded asthma-like symptoms, cough, nasal symptoms and use of medication in a diary from April 1, 2013 to June 30, 2013. To assess exposure to Asian dust, we used Light Detection and Ranging (LIDAR) data. For the analysis of the association between Asian dust and respiratory symptoms, the case-crossover design and generalized estimating equation (GEE) models were used. Taking individual sensitivity to respiratory aggravation into consideration, the subjects were classified into three groups: children without asthma, children with asthma who do not use long-term preventive medication (CA) and children with asthma who use long-term preventive medication (CA-LTM). For CA, Asian dust exposure was significantly associated with asthma-like symptoms, with a hazard ratio of 5.17 (95%CI: 1.02=26.12) at Lag0, and the change in %maxPEF, -1.65% (95%CI:-2.82, -0.48) at Lag0. For children without asthma, a statistically significant association was found between Asian dust exposure and the change in %maxPEF, -0.56% (95%CI: -1.31, -0.08) at Lag1. However, no adverse effects were observed in CA-LTM. Temperature had significant effects on %maxPEF for three groups. Asian dust, photochemical oxidant and pollen caused simultaneously additive adverse effects on nasal symptoms for children without asthma. This study suggests the possibility that long-term preventive medication to manage asthma may suppress aggravation of respiratory symptoms due to Asian dust and may be an effective prevention.

Association between Asian dust exposure and respiratory function in children with bronchial asthma in Nagasaki Prefecture, Japan.

BACKGROUND: Studies on the adverse effects of Asian dust (AD) on respiratory function in children are scarce. The objective of this study was to examine the association between AD and respiratory function by measuring peak expiratory flow rates (PEFRs) in asthmatic children. METHODS: The study was carried out from March to May from 2014 through 2016. One hundred ten children with bronchial asthma were recruited from four hospitals in the Goto Islands and south Nagasaki area in Nagasaki prefecture. The parents were asked to record their children's PEFRs every morning/evening and clinical symptoms in an asthma diary. AD was assessed from light detection and ranging data, and a linear mixed-effects model was used to estimate the effects of AD on daily PEFR. Time-stratified case-crossover analyses were performed to examine the association between AD and asthma attacks defined by reduction levels in PEFR. RESULTS: AD was detected on 11 days in the Goto Islands, and on 23 days in the south Nagasaki area. After adjusting for age, sex, temperature, and daily oxidants, we found a consistent association between AD and a 1.1% to 1.7% decrease in PEFR in the mornings and a 0.7% to 1.3% decrease in the evenings at a lag of 0 to 5 days. AD was not associated with the number of asthma attacks, respiratory symptoms, or other symptoms at any lag days examined. CONCLUSIONS: Exposure to AD was associated with reduced PEFR, although the effects were not large enough to induce clinically apparent symptoms, in clinically well-controlled asthmatic children.

[Health Effects of Asian Dust Events: A Literature Review Update of Epidemiological Evidence].

Asian dust is a phenomenon involving the long-range transport of atmospheric pollutants originating from the desert areas of China and Mongolia. In recent years, the health effects of Asian dust have raised public concerns. Numerous studies on the health effects of Asian dust have been published since the last review in 2010. Thus, a literature review was conducted to shed light on the latest epidemiologic findings. PubMed and Science Direct databases were used for the review of epidemiologic studies published between June 2009 and April 2018. We identified 53 epidemiologic studies. Mortality, ambulance transportation, hospitalization/medical examination, changes in symptomatic, functional, and examination findings, as well as birth outcomes have been reported as outcomes. When the outcomes were categorized by disease, the effects of Asian dust on respiratory, cardiovascular, and allergic diseases raised concerns. The common evidences of causation between Asian dust and these diseases were the consistency of findings and temporal sequence of association. As results of research on dose-response relationships have become available, and the possibility that the health effects of Asian dust may vary depending on its chemical composition has been pointed out, further research using the exposure level indicators of Asian dust or its chemical composition should be conducted. Furthermore, with focus on the crucial issue of reducing exposure, research related to prevention and raising awareness should be further promoted.

Association between daily ambient air pollution and respiratory symptoms in children with asthma and healthy children in western Japan.

OBJECTIVE: In recent years, air pollutant concentrations in Japan have decreased slightly; however, there are growing concerns about the influences of transnational air pollution on respiratory illness. We aimed to clarify the short-term association between the ambient air pollution and respiratory symptoms among children without asthma, children with asthma not using long-term medications (CA-nonLTM), and those using them (CA-LTM). METHODS: A total of 138 children attending 2 primary schools and 71 children with asthma regularly visiting cooperating medical institutions were recruited. Study participants measured peak expiratory flow (PEF) twice a day and recorded coughing, nasal symptoms, and medication use in a diary. Predicted associations between daily air pollutant concentrations and respiratory symptoms, and PEF were evaluated using case-crossover and generalized estimate equation models. RESULTS: Changes in %maxPEF per 10 ppb oxidant (Ox) increase in children without asthma, CA-nonLTM, and CA-LTM were -0.26% (95% CI: -0.49, -0.03), -0.51% (95% CI: -0.89, -0.12), and -0.20% (95% CI: -0.42, 0.01), respectively. The odds ratios for coughing per 10 ppb Ox increase in the Lag0 model were 1.34 (95% CI: 1.11, 1.60), 1.52 (95% CI: 1.12, 2.07), and 1.06 (95% CI: 0.93, 1.20), respectively. These suggested that the Ox concentration has graded effects on %maxPEF and coughing, in the following descending order, CA-nonLTM, children without asthma, and CA-LTM. The Ox concentration was also positively associated with nasal symptoms in children without asthma and CA-LTM. CONCLUSION: Our results suggest that using long-term medications to manage asthma may play an important role in preventing exacerbation of respiratory symptoms due to air pollution.

Influences of low-frequency and other noises produced by wind turbines: An epidemiological literature review.

Objectives　Due to its' environment-friendly and clean energy characteristics, wind power has been increasingly used globally, particularly in advanced countries. However, concerns about health hazards, especially due to low-frequency and other noises generated from wind turbines, have been reported repeatedly. In order to manage adverse health effects appropriately, regulatory standards or guidelines that consider the health of residents need to be developed. To provide a scientific basis for the development of such regulatory standards and guidelines, this paper conducted a literature review to analyze epidemiological studies involving residents living in the vicinity of wind farms.Methods　Using the PubMED database, epidemiological papers that examined the health effects of noises produced by wind turbines were searched and collected. Additional papers were collected from the abstracts presented at relevant international academic conferences such as the Inter-Noise 2013 and Wind Turbine Noise 2015. An evidence table comprising the study design, subjects, exposure assessment, outcomes, confounders, and research results of each selected study was created.Results　A total of 11 papers were collected (2 of which were abstracts from the international academic conferences). These studies reported outcomes such as perception of noises, annoyance caused by the noises, and the association of the noises with stress and sleeplessness. Significant associations between the noises or annoyance produced by wind turbines and subjective adverse health effects were reported repeatedly. Two studies reported an odds ratio of 1.1 for an increase of 1 dB in the A-weighted sound pressure level as a factor representing the influence level. For other factors, it was not possible to compare the magnitude of the impact among the collected studies. Individual attitudes toward wind power and landscapes, economic benefits of wind farms, visibility of wind turbines, sensitivity to sounds, and concerns over health hazards were reported as confounders.Conclusion　Significant associations between the noises or annoyance produced by wind turbines and subjective adverse health effects were reported repeatedly. However, there was insufficient evidence to conclude whether the annoyance was caused by the psychological response to the construction of wind farms or by the actual exposure to noises generated by wind farms.

Association between traffic-related air pollution and asthma in preschool children in a national Japanese nested case-control study.

OBJECTIVES: There has been little study on the effect of traffic-related air pollution on the incidence and persistence of asthma in preschool children. We evaluated the association of exposure to traffic-related air pollution with the incidence/persistence of asthma during the first 3 years of life using a population-based study. METHODS: A baseline survey was conducted in 1½-year-old children (n=63,266). A follow-up survey at 3 years of age (n=43,343) identified new-onset asthma cases (n=853) and persistence of asthma (n=214). In the prevalence/persistence study, the outdoor concentrations of nitrogen oxides (NOx) and elemental carbon (EC) at home during the first 1½â€…years of life were estimated by a dispersion model. In the nested case-control study, which regarded incidence of asthma as cases, the personal exposure levels were estimated by dispersion model including time-activity pattern. RESULTS: There was no statistically significant association between the incidence of asthma between age 1½ and 3 years and personal exposure levels to NOx nor EC. However, the persistence of asthmatic symptoms (between 1½ and 3  ears) was significantly associated with outdoor concentrations of NOx. ORs for the persistence of asthmatic symptoms were 6.02 (95% CI 1.51 to 23.92) for the comparison between the upper 5th and lower 25th centiles of NOx. CONCLUSIONS: While no statistically significant association was observed for the incidence of asthma, the persistence of asthmatic symptoms in preschool children was significantly associated with traffic-related air pollution. This supports its importance as a risk factor in childhood airway disease.

Decline of ambient air pollution levels due to measures to control automobile emissions and effects on the prevalence of respiratory and allergic disorders among children in Japan.

BACKGROUND: In Japan, air pollution due to nitrogen oxides (NOx) and particulate matter (PM) has been gradually reduced since control measures based on the Automobile NOx/PM law were enforced beginning in 2001. The effects of decrease in air pollutants due to the control measures during the past decade on the prevalence of respiratory and allergic disorders such as asthma in children were evaluated. METHODS: Using data of 618,973 children collected in 28 regions of Japan from 1997 to 2009, we evaluated whether reductions in the concentrations of nitrogen dioxide (NO2) and suspended particulate matter (SPM) contribute to the decrease in the prevalence of asthma, wheezing, bronchitis, allergic rhinitis, and atopic dermatitis by multiple linear regression analysis, including adjustments for related factors. RESULTS: The annual rates of decrease in air pollution in the PM-law-enforced areas were 2.0 and 2.5 times higher for NO2 and SPM, respectively, compared with those in the non-enforced areas. The prevalence of asthma decreased significantly at -0.073% per year in the areas in which measures based on the Automobile NOx/PM law were taken but not in area where such measures were not applied. Multiple linear regression analysis showed a reduction in the ambient air pollution was significantly associated with a reduction in the prevalence of asthma, with a rate of 0.118% [95% confidence interval (CI): 0.012-0.225] per 1 ppb for NO2, and 0.050% [95% CI: 0.020-0.080] per 1 µg/m(3) for SPM. An increase in the ambient air pollution was associated with an increase in the prevalence of atopic dermatitis of 0.390% [95% CI: 0.107-0.673] per 1 ppb for NO2, 0.141% [95% CI: 0.058-0.224] per 1 µg/m(3) for SPM. The changes in the prevalence of wheezing and allergic rhinitis were not significantly correlated with changes in air pollutant concentrations. CONCLUSIONS: The enforcement of measures to control automobile emissions based on the Automobile NOx/PM law was shown to have reduced air pollution and contributed to decreases in the prevalence of respiratory and allergic disorders in 3-year-old children.

Storage conditions for stability of offline measurement of fractional exhaled nitric oxide after collection for epidemiologic research.

BACKGROUND: The measurement of fractional concentration of nitric oxide in exhaled air (FeNO) is valuable for the assessment of airway inflammation. Offline measurement of FeNO has been used in some epidemiologic studies. However, the time course of the changes in FeNO after collection has not been fully clarified. In this study, the effects of storage conditions on the stability of FeNO measurement in exhaled air after collection for epidemiologic research were examined. METHODS: Exhaled air samples were collected from 48 healthy adults (mean age 43.4 ± 12.1 years) in Mylar bags. FeNO levels in the bags were measured immediately after collection. The bags were then stored at 4°C or room temperature to measure FeNO levels repeatedly for up to 168 hours. RESULTS: In the bags stored at room temperature after collection, FeNO levels were stable for 9 hours, but increased starting at 24 hours. FeNO levels remained stable for a long time at 4°C, and they were 99.7% ± 7.7% and 101.3% ± 15.0% relative to the baseline values at 24 and 96 hours, respectively. When the samples were stored at 4°C, FeNO levels gradually decreased with time among the subjects with FeNO ≥ 51 ppb immediately after collection, although there were almost no changes among the other subjects. FeNO levels among current smokers increased even at 4°C, although the values among ex-smokers decreased gradually, and those among nonsmokers remained stable. The rate of increase was significantly higher among current smokers than among nonsmokers and ex-smokers from 9 hours after collection onwards. CONCLUSIONS: Storage at 4°C could prolong the stability of FeNO levels after collection. This result suggests that valid measurements can be performed within several days if the samples are stored at 4°C. However, the time course of the changes in FeNO levels differed in relation to initial FeNO values and cigarette smoking.

Relationship between exhaled nitric oxide measured by two offline methods and bronchial hyperresponsiveness in Japanese adults with asthma.

BACKGROUND: Exhaled nitric oxide (eNO) is a useful marker of eosinophilic airway inflammation in asthmatics. There have been no studies to show the relationship between eNO measured by offline methods and the degree of bronchial hyperresponsiveness in asthmatic patients treated with inhaled corticosteroids. METHODS: The study population comprised asthmatics at our outpatient clinic. We measured eNO levels by two methods ("eNOs" was measured with a Sievers kit; and "eNOc" was measured with a kit from the Center for Environmental Information Science, Japan). We also used spirometry to test bronchial hyperresponsiveness to acetylcholine (PC(20Ach)). RESULTS: We recruited 192 stable asthmatics. There was a significant relationship between eNOs and eNOc (r = 0.919, p < 0.001). LogPC(20Ach) levels were negatively correlated with eNOs or eNOc levels (eNOs, r = -0.31, p < 0.001; eNOc, r = -0.23, p = 0.0013). We classified the subjects into two groups based on eNOs levels ((A) the subjects with high eNOs levels (n = 92) and (B) the subjects with normal eNOs levels (n = 100)) ; logPC(20Ach) was significantly correlated with eNOs (r = -0.34, p = 0.001) or eNOc (r = -0.28, p = 0.0075) but not correlated with %FEV(1) in (A), whereas logPC(20Ach) was not significantly correlated with eNO but significantly correlated with %FEV(1) (r = 0.33, p = 0.002) in (B). CONCLUSIONS: Levels of eNOs and eNOc were correlated with the degree of bronchial hyperresponsiveness to acetylcholine in adult asthmatics treated with inhaled corticosteroids. Our findings suggest that offline monitoring of eNO will facilitate the management of bronchial asthma in patients treated with these drugs.