Personal and household PM2.5 and black carbon exposure measures and respiratory symptoms in 8 low- and middle-income countries.

BACKGROUND: Household air pollution (HAP) from cooking with solid fuels has been associated with adverse respiratory effects, but most studies use surveys of fuel use to define HAP exposure, rather than on actual air pollution exposure measurements. OBJECTIVE: To examine associations between household and personal fine particulate matter (PM2.5) and black carbon (BC) measures and respiratory symptoms. METHODS: As part of the Prospective Urban and Rural Epidemiology Air Pollution study, we analyzed 48-h household and personal PM2.5 and BC measurements for 870 individuals using different cooking fuels from 62 communities in 8 countries (Bangladesh, Chile, China, Colombia, India, Pakistan, Tanzania, and Zimbabwe). Self-reported respiratory symptoms were collected after monitoring. Associations between PM2.5 and BC exposures and respiratory symptoms were examined using logistic regression models, controlling for individual, household, and community covariates. RESULTS: The median (interquartile range) of household and personal PM2.5 was 73.5 (119.1) and 65.3 (91.5) µg/m3, and for household and personal BC was 3.4 (8.3) and 2.5 (4.9) x10-5 m-1, respectively. We observed associations between household PM2.5 and wheeze (OR: 1.25; 95%CI: 1.07, 1.46), cough (OR: 1.22; 95%CI: 1.06, 1.39), and sputum (OR: 1.26; 95%CI: 1.10, 1.44), as well as exposure to household BC and wheeze (OR: 1.20; 95%CI: 1.03, 1.39) and sputum (OR: 1.20; 95%CI: 1.05, 1.36), per IQR increase. We observed associations between personal PM2.5 and wheeze (OR: 1.23; 95%CI: 1.00, 1.50) and sputum (OR: 1.19; 95%CI: 1.00, 1.41). For household PM2.5 and BC, associations were generally stronger for females compared to males. Models using an indicator variable of solid versus clean fuels resulted in larger OR estimates with less precision. CONCLUSIONS: We used measurements of household and personal air pollution for individuals using different cooking fuels and documented strong associations with respiratory symptoms.

Measuring and predicting personal and household Black Carbon levels from 88 communities in eight countries.

Black Carbon (BC) is an important component of household air pollution (HAP) in low- and middle- income countries (LMICs), but levels and drivers of exposure are poorly understood. As part of the Prospective Urban and Rural Epidemiological (PURE) study, we analyzed 48-hour BC measurements for 1187 individual and 2242 household samples from 88 communities in 8 LMICs (Bangladesh, Chile, China, Colombia, India, Pakistan, Tanzania, and Zimbabwe). Light absorbance (10-5 m-1) of collected PM2.5 filters, a proxy for BC concentrations, was calculated via an image-based reflectance method. Surveys of household/personal characteristics and behaviors were collected after monitoring. The geometric mean (GM) of personal and household BC measures was 2.4 (3.3) and 3.5 (3.9)·10-5 m-1, respectively. The correlation between BC and PM2.5 was r = 0.76 for personal and r = 0.82 for household measures. A gradient of increasing BC concentrations was observed for cooking fuels: BC increased 53% (95%CI: 30, 79) for coal, 142% (95%CI: 117, 169) for wood, and 190% (95%CI: 149, 238) for other biomass, compared to gas. Each hour of cooking was associated with an increase in household (5%, 95%CI: 3, 7) and personal (5%, 95%CI: 2, 8) BC; having a window in the kitchen was associated with a decrease in household (-38%, 95%CI: -45, -30) and personal (-31%, 95%CI: -44, -15) BC; and cooking on a mud stove, compared to a clean stove, was associated with an increase in household (125%, 95%CI: 96, 160) and personal (117%, 95%CI: 71, 117) BC. Male participants only had slightly lower personal BC (-0.6%, 95%CI: -1, 0.0) compared to females. In multivariate models, we were able to explain 46-60% of household BC variation and 33-54% of personal BC variation. These data and models provide new information on exposure to BC in LMICs, which can be incorporated into future exposure assessments, health research, and policy surrounding HAP and BC.

Multinational prediction of household and personal exposure to fine particulate matter (PM2.5) in the PURE cohort study.

INTRODUCTION: Use of polluting cooking fuels generates household air pollution (HAP) containing health-damaging levels of fine particulate matter (PM2.5). Many global epidemiological studies rely on categorical HAP exposure indicators, which are poor surrogates of measured PM2.5 levels. To quantitatively characterize HAP levels on a large scale, a multinational measurement campaign was leveraged to develop household and personal PM2.5 exposure models. METHODS: The Prospective Urban and Rural Epidemiology (PURE)-AIR study included 48-hour monitoring of PM2.5 kitchen concentrations (n = 2,365) and male and/or female PM2.5 exposure monitoring (n = 910) in a subset of households in Bangladesh, Chile, China, Colombia, India, Pakistan, Tanzania and Zimbabwe. PURE-AIR measurements were combined with survey data on cooking environment characteristics in hierarchical Bayesian log-linear regression models. Model performance was evaluated using leave-one-out cross validation. Predictive models were applied to survey data from the larger PURE cohort (22,480 households; 33,554 individuals) to quantitatively estimate PM2.5 exposures. RESULTS: The final models explained half (R2 = 54%) of the variation in kitchen PM2.5 measurements (root mean square error (RMSE) (log scale):2.22) and personal measurements (R2 = 48%; RMSE (log scale):2.08). Primary cooking fuel type, heating fuel type, country and season were highly predictive of PM2.5 kitchen concentrations. Average national PM2.5 kitchen concentrations varied nearly 3-fold among households primarily cooking with gas (20 µg/m3 (Chile); 55 µg/m3 (China)) and 12-fold among households primarily cooking with wood (36 µg/m3 (Chile)); 427 µg/m3 (Pakistan)). Average PM2.5 kitchen concentration, heating fuel type, season and secondhand smoke exposure were significant predictors of personal exposures. Modeled average PM2.5 female exposures were lower than male exposures in upper-middle/high-income countries (India, China, Colombia, Chile). CONCLUSION: Using survey data to estimate PM2.5 exposures on a multinational scale can cost-effectively scale up quantitative HAP measurements for disease burden assessments. The modeled PM2.5 exposures can be used in future epidemiological studies and inform policies targeting HAP reduction.

Household and personal air pollution exposure measurements from 120 communities in eight countries: results from the PURE-AIR study.

BACKGROUND: Approximately 2·8 billion people are exposed to household air pollution from cooking with polluting fuels. Few monitoring studies have systematically measured health-damaging air pollutant (ie, fine particulate matter [PM2·5] and black carbon) concentrations from a wide range of cooking fuels across diverse populations. This multinational study aimed to assess the magnitude of kitchen concentrations and personal exposures to PM2·5 and black carbon in rural communities with a wide range of cooking environments. METHODS: As part of the Prospective Urban and Rural Epidemiological (PURE) cohort, the PURE-AIR study was done in 120 rural communities in eight countries (Bangladesh, Chile, China, Colombia, India, Pakistan, Tanzania, and Zimbabwe). Data were collected from 2541 households and from 998 individuals (442 men and 556 women). Gravimetric (or filter-based) 48 h kitchen and personal PM2·5 measurements were collected. Light absorbance (10-5m-1) of the PM2·5 filters, a proxy for black carbon concentrations, was calculated via an image-based reflectance method. Surveys of household characteristics and cooking patterns were collected before and after the 48 h monitoring period. FINDINGS: Monitoring of household air pollution for the PURE-AIR study was done from June, 2017, to September, 2019. A mean PM2·5 kitchen concentration gradient emerged across primary cooking fuels: gas (45 µg/m3 [95% CI 43-48]), electricity (53 µg/m3 [47-60]), coal (68 µg/m3 [61-77]), charcoal (92 µg/m3 [58-146]), agricultural or crop waste (106 µg/m3 [91-125]), wood (109 µg/m3 [102-118]), animal dung (224 µg/m3 [197-254]), and shrubs or grass (276 µg/m3 [223-342]). Among households cooking primarily with wood, average PM2·5 concentrations varied ten-fold (range: 40-380 µg/m3). Fuel stacking was prevalent (981 [39%] of 2541 households); using wood as a primary cooking fuel with clean secondary cooking fuels (eg, gas) was associated with 50% lower PM2·5 and black carbon concentrations than using only wood as a primary cooking fuel. Similar average PM2·5 personal exposures between women (67 µg/m3 [95% CI 62-72]) and men (62 [58-67]) were observed. Nearly equivalent average personal exposure to kitchen exposure ratios were observed for PM2·5 (0·79 [95% 0·71-0·88] for men and 0·82 [0·74-0·91] for women) and black carbon (0·64 [0·45-0·92] for men and 0·68 [0·46-1·02] for women). INTERPRETATION: Using clean primary fuels substantially lowers kitchen PM2·5 concentrations. Importantly, average kitchen and personal PM2·5 measurements for all primary fuel types exceeded WHO's Interim Target-1 (35 µg/m3 annual average), highlighting the need for comprehensive pollution mitigation strategies. FUNDING: Canadian Institutes for Health Research, National Institutes of Health.

Is it nutrients, food items, diet quality or eating behaviours that are responsible for the association of children's diet with sleep?

Both diet quality and sleep duration of children have declined in the past decades. Several studies have suggested that diet and sleep are associated; however, it is not established which aspects of the diet are responsible for this association. Is it nutrients, food items, diet quality or eating behaviours? We surveyed 2261 grade 5 children on their dietary intake and eating behaviours, and their parents on their sleep duration and sleep quality. We performed factor analysis to identify and quantify the essential factors among 57 nutrients, 132 food items and 19 eating behaviours. We considered these essential factors along with a diet quality score in multivariate regression analyses to assess their independent associations with sleep. Nutrients, food items and diet quality did not exhibit independent associations with sleep, whereas two groupings of eating behaviours did. 'Unhealthy eating habits and environments' was independently associated with sleep. For each standard deviation increase in their factor score, children had 6 min less sleep and were 12% less likely to have sleep of good quality. 'Snacking between meals and after supper' was independently associated with sleep quality. For each standard deviation increase in its factor score, children were 7% less likely to have good quality sleep. This study demonstrates that eating behaviours are responsible for the associations of diet with sleep among children. Health promotion programmes aiming to improve sleep should therefore focus on discouraging eating behaviours such as eating alone or in front of the TV, and snacking between meals and after supper.

The influence of parental encouragement and caring about healthy eating on children's diet quality and body weights.

OBJECTIVE: In order to mitigate childhood obesity, evidence on what influences children's health behaviours is needed to inform new health promotion strategies. The present study investigated the association between parental practices and their child's diet and body weight status. DESIGN: Grade 5 students and their parents completed health surveys. Parents were asked how much they 'encourage their child to eat healthy foods' and how much they 'personally care about healthy eating'. Children's diet quality and vegetable and fruit intake were assessed using an FFQ. Children's heights and weights were measured to determine body weight status. Mixed-effects regression models were used to determine the influence of parental responses on the outcomes of interest. SETTING: Elementary schools across the province of Alberta, Canada. SUBJECTS: Grade 5 students (aged 10 and 11 years; n 8388) and their parent(s). RESULTS: Most parents reported caring about healthy eating and encouraging their child to eat healthy foods at least quite a lot. Children whose parents who cared or encouraged 'very much' compared with 'quite a lot' were more likely have better diet quality and were less likely to be overweight. Children whose parents both cared and encouraged 'very much' compared with 'quite a lot' scored an average of 2·06 points higher on the diet quality index (ß=2·06; 95 % CI 1·45, 2·66). CONCLUSIONS: Health promotion strategies that aim for a high level of parental interest and encouragement of their children to eat healthy foods may improve diet quality and prevent overweight among children.

Are sleep duration and sleep quality associated with diet quality, physical activity, and body weight status? A population-based study of Canadian children.

OBJECTIVES: To describe sleep duration and sleep characteristics, and to examine the associations between sleep duration and characteristics and body weight status, diet quality, and physical activity levels among grade 5 children in Nova Scotia. METHODS: A provincially representative sample of 5,560 grade 5 children and their parents in Nova Scotia was surveyed. Parents were asked to report their child's bedtime and wake-up time, and to indicate how often their child snored or felt sleepy during the day. Dietary intake and physical activity were selfreported by children using the Harvard Youth/Adolescent Food Frequency Questionnaire and the Physical Activity Questionnaire for Children respectively. Body weight status was determined using measured heights and weights. Linear and logistic random effects models with children nested within schools were used to test for associations. RESULTS: Approximately half of the surveyed parents reported that their children were not getting adequate sleep at night. Longer sleep duration was statistically significantly associated with decreased risk for overweight and obesity independent of other sleep characteristics (OR = 0.82, 95% CI: 0.73, 0.91). Longer sleep duration was also associated with better diet quality and higher levels of physical activity. CONCLUSIONS: These findings indicate a need for health promotion strategies to encourage adequate sleep and to promote healthy sleep environments among children. Given the links among sleep, body weight status and lifestyle behaviours, these messages should be included in public health interventions aimed at preventing obesity and promoting health among children.

The impact of school policies and practices on students' diets, physical activity levels and body weights: A province-wide practice-based evaluation.

OBJECTIVES: To assess what health promotion policies and practices were adopted by schools in Nova Scotia and the extent that these policies and practices affected the diet quality, physical activity (PA) and weight status of students. METHODS: We developed and administered a 'school practice assessment tool' to assess the presence of 72 different school-based health promotion policies and practices. Surveys were conducted in 2003 and 2011 to assess diet, PA and weight status in approximately 10,000 grade 5 students. We used multilevel regression methods to examine changes in these outcomes across schools with varying levels of health promotion policies and practices between the two time-points. RESULTS: Between 2003 and 2011 the diet quality of students improved, PA decreased and the prevalence of childhood obesity increased. Although we did not find consistent or significant favourable benefits resulting from higher implementation levels, we did observe fewer negative trends among schools at higher levels of implementation. CONCLUSION: Our results build on the current gap in knowledge on the impact of Health Promoting Schools (HPS) implementation through population health interventions, but there is a continued need for further evaluation and monitoring of school policies to understand how HPS practices are supporting healthier eating and PA for students.

Leadership skills are associated with health behaviours among Canadian children.

Life skills development is a core area for action in the Ottawa Charter for Health Promotion. The role of life skills in influencing health behaviours among children has received little attention in research. The purpose of this cross-sectional study was to investigate the relationship between self-leadership, as a model of life skills, and diet quality, physical activity, sleep duration and body weight. A provincially representative sample of 2328 grade 5 students (aged 10-11 years) was surveyed in Alberta, Canada. Self-leadership skills were assessed based on student responses indicating frequency of performing various leadership traits. Diet quality was based on responses to the Harvard Youth/Adolescent Food Frequency Questionnaire and physical activity on responses to the Physical Activity Questionnaire for Children. Sleep duration was assessed based on parent survey responses, and body mass index determined based on measured height and weight. Random effects regression models with children nested within schools were used to determine the associations. Higher self-leadership was associated with better diet quality (P < 0.01) and more physical activity (P < 0.01). Although not statistically significant, higher self-leadership was suggestive of healthier body weight status (OR = 0.91, 95% CI = 0.66, 1.27). No association of self-leadership with sleep duration was found. The incorporation of leadership skill development may enhance the effectiveness of school-based health promotion programs. This study reinforces the importance of leadership skill promotion in the promotion of healthy eating and active living, which may help curb the obesity epidemic in the short term, and prevention of chronic diseases and mounting healthcare costs in the long term.

Involvement in meal preparation at home is associated with better diet quality among Canadian children.

OBJECTIVE: To examine the associations between home meal preparation involvement with diet quality and food group intake among children. METHODS: Grade 5 children aged 10-11 years (n = 3,398) were surveyed. Food intake was measured using the Harvard Youth/Adolescent Food Frequency Questionnaire, and diet quality was measured using the Diet Quality Index-International. Random effects regression models with children nested within schools were used to test for associations. RESULTS: Higher frequency of involvement in home meal preparation was associated with higher Diet Quality Index-International scores. Children who were involved in meal preparation daily ate 1 more serving/d of vegetables and fruit compared with children who never helped (P < .001). Similar significant differences, although small, were observed for intake of the other food groups. CONCLUSIONS AND IMPLICATIONS: Children who were more involved in home meal preparation also consumed healthier diets. Encouraging parents to involve their children in meal preparation could be a viable health promotion strategy.

Fruit and vegetable preferences and intake among children in Alberta.

PURPOSE: The association between preference for and intake of fruits and vegetables was examined among Albertan children. METHODS: Data used were collected as part of a provincial population-based survey among grade 5 children in Alberta. Intake of two fruits and five vegetables was assessed using the Harvard food frequency questionnaire, and preference for individual fruit and vegetable items was rated using a three-point Likert-type scale. Random effects models with children nested within schools were used to test for associations between fruit and vegetable preference and intake. RESULTS: A total of 3398 children aged 10 to 11 years returned completed surveys. Children who reported a greater liking for fruits and vegetables also reported significantly (p<0.001) higher intake. On average, children who liked a food a lot ate 0.5 to 2.7 more weekly servings of the food than did children who did not like the food. CONCLUSIONS: These findings suggest that focusing on interventions designed to increase taste preference may lead to increased fruit and vegetable intake among children. Introducing children to unfamiliar fruits and vegetables through taste testing may be an effective and practical health promotion approach for improving dietary habits.

Involvement in home meal preparation is associated with food preference and self-efficacy among Canadian children.

OBJECTIVE: To examine the association between frequency of assisting with home meal preparation and fruit and vegetable preference and self-efficacy for making healthier food choices among grade 5 children in Alberta, Canada. DESIGN: A cross-sectional survey design was used. Children were asked how often they helped prepare food at home and rated their preference for twelve fruits and vegetables on a 3-point Likert-type scale. Self-efficacy was measured with six items on a 4-point Likert-type scale asking children their level of confidence in selecting and eating healthy foods at home and at school. SETTING: Schools (n =151) located in Alberta, Canada. SUBJECTS: Grade 5 students (n = 3398). RESULTS: A large majority (83-93 %) of the study children reported helping in home meal preparation at least once monthly. Higher frequency of helping prepare and cook food at home was associated with higher fruit and vegetable preference and with higher self-efficacy for selecting and eating healthy foods. CONCLUSIONS: Encouraging children to be more involved in home meal preparation could be an effective health promotion strategy. These findings suggest that the incorporation of activities teaching children how to prepare simple and healthy meals in health promotion programmes could potentially lead to improvement in dietary habits.

A qualitative study to explore how parental expectations and rules influence beverage choices in early adolescence.

OBJECTIVE: To understand parent beverage expectations for early adolescents (EAs) by eating occasion at home and in various settings. METHODS: Descriptive study using focus group interviews and the constant comparative method for qualitative data analysis. RESULTS: Six focus groups were completed, and 2 were conducted in Spanish. Participants (n = 49) were mostly female (86%) and non-Hispanic white (49%) and Hispanic (33%). Parent expectations for EA beverage intake were based on health beliefs, EA preferences, and cost, whereas those related to portion sizes and frequency varied by beverage type. Parents managed beverage expectations at home and away from home by making healthful beverages available and accessible, or by offering or allowing only specific beverages. CONCLUSIONS AND IMPLICATIONS: Results from this qualitative study involving a small sample of parents showed that expectations were influenced by practical concerns and managed primarily through availability practices. These issues could be addressed to improve EA beverage consumption.

School foodservice personnel's struggle with using labels to identify whole-grain foods.

OBJECTIVE: To describe how school foodservice personnel use current labeling methods to identify whole-grain products and the influence on purchasing for school meals. METHODS: Focus groups explored labeling methods to identify whole-grain products and barriers to incorporating whole-grain foods in school meals. Qualitative analysis procedures and the constant comparative method were used to analyze data. RESULTS: Participants were school foodservice personnel (n = 67) in 5 states across the United States. Limited ability and confidence were demonstrated in identifying whole-grain products from label information, statements, and claims. Participants indicated a need for a uniform labeling method such as whole-grain content to assist in ordering and purchasing. High cost and low acceptability were listed as barriers to incorporating whole-grain foods in school meals. CONCLUSIONS AND IMPLICATIONS: Whole-grain product labeling should be improved to enhance understanding by foodservice personnel so that whole grains are included in school meals.

Time spent in home meal preparation affects energy and food group intakes among midlife women.

Time spent in meal preparation may be indicative of the healthfulness of meals and therefore with weight status. The purpose of this study was to examine the association between amount of time spent preparing meals and meal food group and nutrient content by meal occasion (breakfast, lunch, and dinner) among 1036 midlife women. Participants completed a 1-day food record and eating occasion questionnaires for each meal occasion. ANCOVA was used to identify possible associations. Approximately half of the participants reported spending <5 min preparing breakfast and lunch, and <20 min preparing dinner. Less time spent preparing breakfast was associated with lower energy and fat intakes (p<0.0001), while less time spent preparing lunch and dinner was associated with lower vegetable and sodium intakes (p<0.0001). There were no apparent differences in the association between time spent preparing meals and meal content by weight status. Nutrition education should encourage home meal preparation while stressing the selection of healthier options. The differing associations by meal occasion suggest that interventions should be tailored according to meal type.

Acceptance of two US Department of Agriculture commodity whole-grain products: a school-based study in Texas and Minnesota.

Whole-grain intake among children and adolescents is below national recommendations, prompting efforts to increase intake in schools. The purpose of this study was to compare the acceptance of whole-grain pancakes and tortillas to refined grain counterparts when served as part of the school meal. Data were collected at 10 schools in Minnesota and seven schools in Texas during the Spring and Fall semesters of 2009. Three pancake and two tortilla products of varying red or white whole-wheat flour content were each served an average of four times per school. Aggregate plate waste was collected and percent consumption used to assess acceptance. Students rated each product on overall liking, taste, color, and softness on 5-point (elementary schools) or 9-point hedonic scales (middle and high schools). Analysis of covariance was used to compare intake and rating scores of all products. For all children, intake of whole-grain products was substantial (percent consumption ranging from 67% to 75%). No differences were noted in consumption of whole-wheat pancakes compared to refined wheat pancakes, while consumption of whole-wheat tortillas was lower than refined products. In elementary schools, overall liking scores of pancakes made with red whole-wheat and both types of whole-wheat tortillas were lower than refined products. However, in middle and high schools, overall liking scores of 100% red whole-wheat pancakes and 66% white whole-wheat tortillas were similar to refined products. Substituting refined grain with whole-grain options represents a viable approach to increasing consumption of whole-grain products in schools.