Obesity, tidal volume, and pulmonary deposition of fine particulate matter in children with asthma.

BACKGROUND: Obese children with asthma are more vulnerable to air pollution, especially fine particulate matter (PM2.5), but reasons are poorly understood. We hypothesised that differences in breathing patterns (tidal volume, respiratory rate and minute ventilation) due to elevated body mass index (BMI) may contribute to this finding. OBJECTIVE: To investigate the association of BMI with breathing patterns and deposition of inhaled PM2.5. METHODS: Baseline data from a prospective study of children with asthma were analysed (n=174). Tidal breathing was measured by a pitot-tube flowmeter, from which tidal volume, respiratory rate and minute ventilation were obtained. The association of BMI z-score with breathing patterns was estimated in a multivariable model adjusted for age, height, race, sex and asthma severity. A particle dosimetry model simulated PM2.5 lung deposition based on BMI-associated changes in breathing patterns. RESULTS: Higher BMI was associated with higher tidal volume (adjusted mean difference (aMD) between obese and normal-range BMI of 25 mL, 95% CI 5-45 mL) and minute ventilation (aMD 453 mL·min-1, 95% CI 123-784 mL·min-1). Higher tidal volumes caused higher fractional deposition of PM2.5 in the lung, driven by greater alveolar deposition. This translated into obese participants having greater per-breath retention of inhaled PM2.5 (aMD in alveolar deposition fraction of 3.4%, 95% CI 1.3-5.5%), leading to worse PM2.5 deposition rates. CONCLUSIONS: Obese children with asthma breathe at higher tidal volumes that may increase the efficiency of PM2.5 deposition in the lung. This finding may partially explain why obese children with asthma exhibit greater sensitivity to air pollution.

Patterns and predictors of air purifier adherence in children with asthma living in low-income, urban households.

OBJECTIVE: Black children and children from low-income communities are disproportionately affected by asthma, attributed partly to pollution exposure. Air purifiers reduce indoor air pollution and improve asthma symptoms in children. In order to implement air purifier interventions, an understanding of patterns of use and potential barriers is necessary. METHODS: In a home intervention study, 127 children with asthma living in Baltimore were randomized to receive two active or two placebo air purifiers. The 16-week study period included: baseline clinic visit, home visit for air purifier installation (active or placebo) with instruction to use the high or turbo settings, and electronic adherence monitoring of air purifiers. Determinants of adherence were identified using linear regression models. RESULTS: Air purifiers were used 80% of the time, and participants demonstrated adherence to high or turbo settings for 60% of the time. In an adjusted model, season was the major determinant of air purifier adherence, with 21% lower use in the winter (p = 0.025) attributed to the cold draft generated by the machine. CONCLUSION: In a clinical trial with electronic adherence monitoring, air purifier use was high and participants were adherent to use of high or turbo settings the majority of the time. Addressing practical barriers to consistent use, such as draft during the winter, in addition to financial barriers may improve air purifier adherence among children with asthma living in low-income, urban households. CLINICAL TRIALS REGISTRY NUMBER: NCT02763917.

Spatial analysis of tobacco outlet density on secondhand smoke exposure and asthma health among children in Baltimore City.

RATIONALE: Tobacco outlets are concentrated in low-income neighbourhoods; higher tobacco outlet density is associated with increased smoking prevalence. Secondhand smoke (SHS) exposure has significant detrimental effects on childhood asthma. We hypothesised there was an association between higher tobacco outlet density, indoor air pollution and worse childhood asthma. METHODS: Baseline data from a home intervention study of 139 children (8-17 years) with asthma in Baltimore City included residential air nicotine monitoring, paired with serum cotinine and asthma control assessment. Participant addresses and tobacco outlets were geocoded and mapped. Multivariable regression modelling was used to describe the relationships between tobacco outlet density, SHS exposure and asthma control. RESULTS: Within a 500 m radius of each participant home, there were on average six tobacco outlets. Each additional tobacco outlet in a 500 m radius was associated with a 12% increase in air nicotine (p<0.01) and an 8% increase in serum cotinine (p=0.01). For every 10-fold increase in air nicotine levels, there was a 0.25-point increase in Asthma Therapy Assessment Questionnaire (ATAQ) score (p=0.01), and for every 10-fold increase in serum cotinine levels, there was a 0.54-point increase in ATAQ score (p<0.05). CONCLUSIONS: Increased tobacco outlet density is associated with higher levels of bedroom air nicotine and serum cotinine. Increasing levels of SHS exposure (air nicotine and serum cotinine) are associated with less controlled childhood asthma. In Baltimore City, the health of children with asthma is adversely impacted in neighbourhoods where tobacco outlets are concentrated. The implications of our findings can inform community-level interventions to address these health disparities.

Recent use of consumer and personal care products and exposures to select endocrine disrupting chemicals among urban children with asthma.

BACKGROUND: Emerging studies suggest that endocrine disrupting chemicals (EDCs) in personal care and other consumer products are linked with various adverse health effects, including respiratory and reproductive effects. Despite Black persons using more personal care products than other demographic groups and having a high asthma burden, little is known regarding their consumer product use patterns and associated EDC exposures. OBJECTIVE: To examine the association between recent exposure to select EDCs with specific consumer products and behaviors in a cohort of 110 predominantly Black children with asthma, ages 8-17 years, living in Baltimore City, Maryland. METHODS: We quantified concentrations of bisphenol A (BPA), bisphenol S (BPS), bisphenol F, two dichlorophenols, four parabens, triclosan, benzophenone-3, and triclocarban in spot urine samples. Questionnaires were used to capture recent (last 24-h) consumer product use and behaviors. Associations between EDCs and consumer product uses/behaviors were assessed using multivariable linear regression, adjusting for age, gender, race/ethnicity, and caregiver income level. Effect estimates were expressed as geometric mean ratios of biomarker concentrations of product-users vs non-users. RESULTS: Increased concentrations to select EDCs were associated with recent use of air freshener (ratios; BPA: 1.9, 95%CI 1.4-2; BPS 1.7, 95%CI 1-2.97; propyl paraben: 3.0, 95%CI 1.6-5.6), scented candles (methyl paraben: 2.6, 95%CI 1.1-6.1), and scented carpet powder (2,5-dichlorophenol: 2.8, 95%CI 1.2-6.3). Additionally, consuming canned food was associated with some increased biomarker concentrations (ratios: BPA: 1.7, 95%CI 1.2-2.4; BPS: 2.1, 95% CI: 1.2-3.6). SIGNIFICANCE: These findings add to the body of evidence suggesting that recent use of select consumer products in Black children contributes to exposure of chemicals of concern and could potentially inform exposure mitigation interventions. Findings have broad potential health implications for pediatric populations and Black children who may face exposure and health disparities. IMPACT: Little is known about how children's personal care product use and consumer behaviors affect their exposures to endocrine disrupting chemicals (EDCs). This is particularly true for Black children who often experience a disparate exposure burden to many EDCs. This is a significant knowledge gap among children that are uniquely vulnerable to EDCs as they undergo critical windows of growth and development. Our findings show associations between consumer products and EDC exposures in predominantly Black children in low-income settings. Identifying EDC exposure determinants has broad health implications as many of these chemicals have been associated with adverse health risks.

Obstructive sleep apnea screening in children with asthma.

RATIONALE: Obstructive sleep apnea is highly prevalent in children with asthma, particularly in obese children. The sleep-related breathing disorder screening questionnaire has low screening accuracy for obstructive sleep apnea in children with asthma. Our goal was to identify the questions on the sleep-related breathing disorder survey associated with obstructive sleep apnea in children with asthma. METHODS: Participants completed the survey, underwent polysomnography and their body mass index z-score was measured. Participants with survey scores above 0.33 were considered high risk for obstructive sleep apnea and those with an apnea-hypopnea index ≥ 2 events/h classified as having obstructive sleep apnea. Logistic regression was used to examine the association of each survey question and obstructive sleep apnea. Positive and negative predictive values were calculated to estimate screening accuracy. RESULTS: The prevalence of obstructive sleep apnea was 40% in our sample (n = 136). Loud snoring, morning dry mouth, and being overweight were the survey questions associated with obstructive sleep apnea. The composite survey score obtained from all 22 questions had positive and negative predictive values of 51.0% and 65.5%, while the combined model of loud snoring, morning dry mouth, and being overweight had positive and negative predictive values of 60.3% and 77.6%. On the other hand, the body mass index z-score alone had positive and negative predictive values of 76.3% and 72.2%. CONCLUSIONS: The body mass index z-score is useful for obstructive sleep apnea screening in children with asthma and should be applied routinely given its simplicity and concerns that obstructive sleep apnea may contribute to asthma morbidity.

The Lung Health Ambassador Program: A Community-Engagement Initiative Focusing on Pulmonary-Related Health Issues and Disparities Regarding Tobacco Use.

Introduction: Educational campaigns have the potential to inform at risk populations about key issues relevant to lung health and to facilitate active engagement promoting healthy behaviors and risk prevention. We developed a community-based educational campaign called the Lung Health Ambassador Program (LHAP) with a goal of engaging youth and empowering them to be advocates for pulmonary health in their community. Objective: To evaluate the process outcomes and feasibility of the inaugural LHAP (2018-2019 academic year), with a specific aim to impact tobacco policy in the state of Maryland. Methods: Outcomes regarding feasibility included assessment of number of schools reached, number of students and healthcare professionals participating, and types of projects developed by participating students to impact modifiable risk factors for lung health. The courses for the LHAP were five 1 h sessions implemented at days and times identified by the community. The topics of the LHAP focused on lung anatomy, pulmonary diseases affecting school aged youth, tobacco use and prevalence, and air pollution (both indoor and outdoor). The fifth class discussed ways in which the students could impact lung health (e.g., policy and advocacy) and mitigate pulmonary disparities. Main Results: The LHAP was implemented at two elementary/middle schools, one high school, and two recreation centers within an urban metropolitan region. A total of 268 youths participated in the LHAP (age ranging from 11 to 18), whereby 72 (26.9%) were Hispanic/Latino and 110 (41.0%) were African American. Of the participating students, 240 wrote letters to local politicians to advocate for policies that would raise the legal age of acquiring tobacco products to 21. As for healthcare professionals, 18 academic faculty members participated in implementing the LHAP: 8 physicians and faculty staff and 10 nurses. Conclusions: The LHAP is a community-based program that provides education and training in advocacy with a goal of teaching about and, ultimately, reducing respiratory health disparities. The results from the first year demonstrate that the program is feasible, with success demonstrated in completing educational modules and engaging students. Next steps will include strategies to ensure sustainability and scalability to increase the reach of this program.

Proposal for smoke-free public housing: a systematic review of attitudes and preferences from residents of multi-unit housing.

A policy proposal to ban public housing smoking indoors has received support, but it is unclear how certain affected groups, specifically smokers in housing units, perceive such a policy. To review the literature on attitudes and perceptions of housing unit tenants towards an indoor smoke-free housing policy, using various databases, we searched articles for attitudes towards smoking ban enforcement in housing units. We identified fourteen articles. Non-smokers heavily favored indoor policies and current smokers heavily opposed them. Current smokers represented a substantial minority in the reviewed articles, resulting in overall outcomes of the surveys driven by non-smokers. Studies investigating attitudes about housing smoking bans largely represent the views of non-smokers and lack data about barriers and concerns of tenants who do not support a smoke-free policy. Future studies should investigate if such a discrepancy impacts the efficacy of smoke-free housing policies.