Indoor particle counts during Asian dust events under everyday conditions at an apartment in Japan

Association of air purifier usage during pregnancy with adverse birth outcomes: the Japan Environment and Children's Study

OBJECTIVE

Previous studies have reported that ambient air pollutants such as PM2.5 can increase the risk of adverse birth outcomes. The objective of this study was to ascertain whether air purifier usage during pregnancy is associated with a lower risk of adverse birth outcomes in a large Japanese birth cohort.

METHODS

We conducted a prospective cohort analysis using data from the Japan Environment and Children's Study. Use of air purifiers during pregnancy was assessed using a self-administered questionnaire. Primary outcomes were the prevalence of preterm birth (PTB), small for gestational age (SGA), and low birth weight (LBW). Logistic regression analysis was performed to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The prevalence of outcomes was 4.5% for PTB, 7.4% for SGA, and 8.1% for LBW. The crude model analysis revealed that PTB, SGA, and LBW showed lower ORs in the group that used an air purifier, although the association disappeared in the adjusted model except for SGA (OR: 0.94; 95% CI: 0.89, 1.00, p = 0.048) and LBW (OR: 0.93; 95% CI: 0.88, 0.98, p = 0.003). Subgroup analysis stratified by infant sex revealed that the lower OR for LBW was observed only in male infants.

CONCLUSIONS

Our results suggest that avoiding maternal air pollution exposure during pregnancy may be useful in preventing adverse birth outcomes. These findings provide evidence supporting the development of protective measures against air pollutants in the gestational period by relevant health agencies.

Randomised controlled trial of a behavioural intervention to reduce exposure to PM2.5 in patients with COPD

BACKGROUND

Fine particulate matter (PM2.5) is a well-known risk factor for worse outcomes of chronic obstructive pulmonary disease (COPD). However, evidence-based guidance on effective personal behavioural strategies to minimise the effects of PM2.5 is limited. This study aimed to assess the effectiveness of a behavioural intervention in reducing PM2.5 exposure and improving clinical outcomes in patients with COPD.

MATERIALS AND METHODS

Participants were 1:1 randomised, and the intervention group received a behavioural intervention consisting of five activities, while the control group received usual care. The participants were followed up for 9 months. The primary outcomes were differences in the score of St. George's Respiratory Questionnaire for patients with COPD (SGRQ-C) and COPD assessment test (CAT) from baseline.

RESULTS

A total of 106 participants were enrolled and 102 completed the study. At the end of the study, the intervention group showed significant improvements in the primary outcomes compared to the control group, with a group difference of -5.9 in the reduction of total SGRQ-C (-3.4 vs. 2.5; p = 0.049) and -3.8 in the CAT score (-1.2 vs. 2.7; p = 0.001). Participants with good adherence to the intervention demonstrated a greater extent of improvement in CAT score and lower PM2.5 levels compared to those who had poor adherence or were in the control group. Regular checking of air quality forecasts was significantly associated with a reduction in CAT scores among all the intervention activities.

CONCLUSION

Individual-level behavioural interventions can be an effective strategy for mitigating the health hazards associated with PM2.5.

CLINICALTRIALS

gov Identifier: NCT04878367.

Prospective association of air purifier use during pregnancy with the neurodevelopment of toddlers in the Japan Environment and Children's Study

We examined the association between maternal air purifier use during pregnancy and neurodevelopmental delay in toddlers by analysing data from 82,457 mother-toddler pairs. Air purifier use was measured using a simple yes/no question. Developmental delays at 1.5, 2.0, 2.5, and 3.0 years were assessed using the Ages and Stages Questionnaire, Third Edition. Generalized additive mixed model analysis with 21 covariates revealed that air purifier use was associated with lower prevalence of developmental delay in all five areas—communication, gross motor, fine motor, problem solving, and personal-social—at all four time points (adjusted risk ratios ranged from 0.827 to 0.927, and only one 95% confidence interval crossed the reference). These findings suggest a negative association between air purifier use during pregnancy and neurodevelopmental delay in toddlers.

Trial registration: UMIN000030786 (15/01/2018).

Personal-Level Protective Actions Against Particulate Matter Air Pollution Exposure: A Scientific Statement From the American Heart Association

Since the publication of the last American Heart Association scientific statement on air pollution and cardiovascular disease in 2010, unequivocal evidence of the causal role of fine particulate matter air pollution (PM2.5, or particulate matter ≤2.5 μm in diameter) in cardiovascular disease has emerged. There is a compelling case to provide the public with practical personalized approaches to reduce the health effects of PM2.5. Such interventions would be applicable not only to individuals in heavily polluted countries, high-risk or susceptible individuals living in cleaner environments, and microenvironments with higher pollution exposures, but also to those traveling to locations with high levels of PM2.5. The overarching motivation for this document is to summarize the current evidence supporting personal-level strategies to prevent the adverse cardiovascular effects of PM2.5, guide the use of the most proven/viable approaches, obviate the use of ineffective measures, and avoid unwarranted interventions. The significance of this statement relates not only to the global importance of PM2.5, but also to its focus on the most tested interventions and viable approaches directed at particulate matter air pollution. The writing group sought to provide expert consensus opinions on personal-level measures recognizing the current uncertainty and limited evidence base for many interventions. In doing so, the writing group acknowledges that its intent is to assist other agencies charged with protecting public health, without minimizing the personal choice considerations of an individual who may decide to use these interventions in the face of ongoing air pollution exposure.

Prospective Association of Air-Purifier Usage during Pregnancy with Infant Neurodevelopment: A Nationwide Longitudinal Study-Japan Environment and Children's Study (JECS)

Fetal exposure to particulate matter (PM) is associated with infant developmental delay likely via neuroinflammation and prefrontal cortex lesions; however, whether air-purifier usage, which can reduce indoor PM levels, is related to infant developmental delay remains unknown. We therefore examined the prospective relationship between air-purifier usage during pregnancy and infant developmental delay by analyzing 82,441 mother-infant pairs using a simple yes/no questionnaire. Developmental delays at 6 and 12 months were assessed in five areas using the Ages and Stages Questionnaire, Third Edition. A generalized linear mixed model analysis was used to derive adjusted odds ratios (AORs) and 95% confidence intervals (95% CIs) while controlling for 20 covariates. The analysis revealed that air-purifier usage was associated with developmental delays in fine motor (AOR: 0.91, 95% CI: 0.83-0.99) and problem solving (AOR: 0.83, 95% CI: 0.77-0.90) at 6 months and in communication (AOR: 0.86, 95% CI: 0.79-0.93), fine motor (AOR: 0.87, 95% CI: 0.82-0.92), problem solving (AOR: 0.83, 95% CI: 0.77-0.88), and personal-social (AOR: 0.79, 95% CI: 0.72-0.86) at 12 months. In conclusion, a negative association exists between air-purifier usage during pregnancy and infant neurodevelopmental delay that strengthens with time. Our results outline the potential role of air purifiers in inhibiting infant neurodevelopmental delay.

The impact of exposure to desert dust on infants' symptoms and countermeasures to reduce the effects

BACKGROUND

The association between particulate matter (PM), including desert dust, and allergic symptoms has not been well studied. We examined whether PM exacerbated nose/eye/respiratory symptoms in infants, with a focus on the desert dust element, and assessed possible countermeasures.

METHODS

We conducted a panel study of 1492 infants from October 2014 to July 2016 in 3 regions in Japan as an adjunct study of the Japan Environment and Children's Study. Infants' daily symptom scores and behaviors were acquired by web-based questionnaires sent to mothers, who answered within a day using mobile phones. Odds ratios (OR) for symptom development per increased fine PM or desert dust exposure were estimated. Regular use of medications and behaviors on the day of exposure were investigated as possible effect modifiers.

RESULTS

Infants developed nose/eye/respiratory symptoms significantly more often in accordance with fine particulate levels (adjusted OR per 10 µg/m³ increase: 1.04, 95% confidence interval [CI]: 1.01-1.07). A model including both fine particulates and desert dust showed reduced OR for fine particulates and robust OR for desert dust (adjusted OR per 0.1/km increase: 1.16, 95% CI: 1.09-1.23). An increased OR was observed both in infants who had previously wheezed and in those who had never wheezed. Receiving information on the particulate forecast, reducing time outdoors, closing windows, and regular use of leukotriene receptor antagonists were significant effect modifiers.

CONCLUSIONS

Transborder desert dust arrival increased the risk of nose/eye/respiratory symptoms development in infants. Regular use of leukotriene receptor antagonists and other countermeasures reduced the risk.

[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.

Birth cohort study on the effects of desert dust exposure on children's health: protocol of an adjunct study of the Japan Environment & Children's Study

INTRODUCTION

Desert dust is estimated to constitute about 35% of aerosol in the troposphere. Desertification, climatic variability and global warming all can contribute to increased dust formation. This study aims to examine possible health effects of desert dust exposure on pregnant women and their children. The purpose of this report was to present the study protocol.

METHODS AND ANALYSIS

This 4-year birth cohort study began in 2011 as an adjunct study of the Japan Environment & Children's Study (JECS) involving three regions: Kyoto, Toyama and Tottori. The JECS participants of the three regions above who also agreed to participate in this adjunct study were enrolled prior to delivery. Light Detecting and Ranging (LIDAR) with a polarisation analyser, which can distinguish mineral dust particles from other particles, is used for exposure measurements. Outcomes are allergic symptoms for mothers and development of asthma and other allergic or respiratory diseases for their children. Data are acquired in a timely manner by connecting local LIDAR equipment to an online questionnaire system. Participants answer the online questionnaire using mobile phones or personal computers.

ETHICS AND DISSEMINATION

The study protocol was approved by the ethics committees of Kyoto University, University of Toyama and Tottori University. All participants provided written informed consent. The results of this study will be published in peer-reviewed journals and disseminated to the scientific community and general public.

TRIAL REGISTRATION NUMBER

UMIN000010826.