Variation of NO2 and NOx concentrations between and within 36 European study areas: Results from the ESCAPE study

n/

Spatial variation of PM2.5, PM10, PM2.5 absorbance and PMcoarse concentrations between and within 20 European study areas and the relationship with NO2 - Results of the ESCAPE project

n/

Early-Life Determinants of Total and HDL Cholesterol Concentrations in 8-Year-Old Children; The PIAMA Birth Cohort Study

BACKGROUND: Adult cholesterol concentrations might be influenced by early-life factors, such as breastfeeding and birth weight, referred to as "early programming". How such early factors exert their influence over the life course is still poorly understood. Evidence from studies in children and adolescents is scarce and conflicting. We investigated the influence of 6 different perinatal risk factors on childhood total and HDL cholesterol concentrations and total-to-HDL cholesterol ratio measured at 8 years of age, and additionally we studied the role of the child's current Body Mass Index (BMI). METHODS: Anthropometric measures and blood plasma samples were collected during a medical examination in 751 8-year-old children participating in the prospective Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study. Linear and logistic regression were performed to estimate associations of total and HDL cholesterol concentrations with breastfeeding, birth weight, infant weight gain, maternal overweight before pregnancy, gestational diabetes and maternal smoking during pregnancy, taking into account the child's current BMI. RESULTS: Linear regressions showed an association between total-to-HDL cholesterol ratio and maternal pre-pregnancy overweight (β = 0.15, Confidence Interval 95% (CI): 0.02, 0.28), rapid infant weight gain (β = 0.13, 95%CI: 0.01, 0.26), and maternal smoking during pregnancy (β = 0.14, 95%CI: 0.00, 0.29). These associations were partly mediated by the child's BMI. CONCLUSION: Total-to-HDL cholesterol ratio in 8-year-old children was positively associated with maternal pre-pregnancy overweight, maternal smoking during pregnancy and rapid infant weight gain

Respiratory health effects of ultrafine and fine particle exposure in cyclists.

OBJECTIVES: Monitoring studies have shown that commuters are exposed to high air pollution concentrations, but there is limited evidence of associated health effects. We carried out a study to investigate the acute respiratory health effects of air pollution related to commuting by bicycle. METHODS: Twelve healthy adults cycled a low- and a high-traffic intensity route during morning rush hour in Utrecht, The Netherlands. Exposure to traffic-related air pollution was characterised by measurements of PM(10), soot and particle number. Before, directly after and 6 h after cycling we measured lung function (FEV(1), FVC, PEF), exhaled NO (FE(NO)) and respiratory symptoms. The association between post- minus pre-exposure difference in health effects and exposure during cycling was evaluated with linear regression models. RESULTS: The average particle number concentration was 59% higher, while the average soot concentration was 39% higher on the high-traffic route than on the low-traffic route. There was no difference for PM(10). Contrary to our hypothesis, associations between air pollution during cycling and lung function changes immediately after cycling were mostly positive. Six hours after cycling, associations between air pollution exposure and health were mostly negative for lung function changes and positive for changes in exhaled NO, although non-significant. CONCLUSIONS: We found substantial differences in ultrafine particle number and soot exposure between two urban cycling routes. Exposure to ultrafine particles and soot during cycling was weakly associated with increased exhaled NO, indicative of airway inflammation, and decrements in lung function 6 h after exposure. A limitation of the study was the relatively small sample size

Gas cooking, kitchen ventilation, and exposure to combustion products

We evaluated a questionnaire-based system for classifying homes into groups with distinctly different chances of accumulating combustion products from cooking appliances. The system was based on questions about type of cooking appliance, type and use of ventilation provisions, and kitchen size. Real-time measurements were made of CO, CO2, temperature, and water vapor, and passive sampling was performed of nitrogen oxides, over a week-long period in 74 kitchens. During the measurements, inhabitants kept a diary to record appliance use time and use of ventilation provisions. The questionnaire-based and diary-based home classifications for the 'Chance of Accumulation of Combustion Products' (CACP) turned out to agree fairly well. For CO2 as well as for CO a significant difference between the 'high' and 'low' CACP groups was found for the mean accumulation in the kitchen during cooking of the combustion generated concentrations. These facts are considered to be important experimental evidence of the CACP stratification being valid for our study population. In the homes studied, NO2 as well as CO concentrations were found to be lower compared with previous studies in The Netherlands

Determinants of house dust endotoxin in three European countries – the AIRALLERG study.

The comparison of endotoxin levels between study populations and countries is limited as a result of differences in sampling, extraction, and storage procedures. The objective of this study is to assess the levels and determinants of endotoxin in mattress and living room floor dust samples from three European countries, namely, Germany, the Netherlands, and Sweden, using a standardized sampling, storage, and analysis protocol. The mattress and living room floor dust was collected from the homes of 1065 German, Dutch, and Swedish (pre-)school children. All the samples were collected in the cool season and analyzed for endotoxin in a central laboratory. The determinants were assessed by a standardized questionnaire. The endotoxin concentrations in mattress and living room floor dust were found to be the highest in German homes and lowest in the Swedish ones. Differences between the geometric means were small (factor 1.1–1.7). Most of the associations between endotoxin concentrations and potential determinants were not statistically significant and heterogeneous across countries. However, keeping pets and having more than four persons living in the home were consistently associated with up to 1.7-fold higher endotoxin concentrations in mattress and floor dust. Furthermore, having carpets or rugs, and opening the windows frequently was associated with up to 3.4-fold and 1.3-fold higher endotoxin concentrations in living room floor dust, respectively. The proportion of variance explained by the questionnaire variables was generally low. In conclusion, the data on housing characteristics did not accurately predict the endotoxin concentrations in house dust, and could only partly explain the differences between countries

Variation of biocontaminant levels within and between homes--the AIRALLERG study.

Few epidemiological studies report on reliability of exposure measurements even though this significantly influences the results of correlation and regression analysis often used in these studies. Poor reliability of exposure measurement reduces the ability to detect a true association between a certain component and health outcome variables. The aim of this study was to determine the ratio of the within-home and between-home components of variance of a number of biocontaminants measured in house dust in the framework of an international study conducted in the Netherlands, Germany and Sweden (the AIRALLERG study). To this end, duplicate dust samples were collected from children's beds and from living room floors in over 100 homes. Samples were taken at the same point in time. Variables considered were the dust mass collected in mg/m2 and the concentrations of the house dust mite allergens Der p 1 and Der f 1, cat allergen Fel d 1, endotoxin, (1 --> 3)-beta-D-glucan and extracellular polysaccharides, all per gram of dust and per square meter of sampling surface. An analysis of variance showed that the within-home variance was small compared to the between-home variance for most variables (mostly less than half) with the exception of glucan on mattresses, when expressed in mug/g. Investigation of variation over time is needed for a more complete assessment of the use of these variables in epidemiological analyses of exposure-response relationships

Using nicotine measurements and parental reports to assess indoor air:The PIAMA birth cohort study

We used two methods to collect data on indoor smoking exposure of 3-month-old infants. First, parents of approximately 100 children completed a questionnaire. We then measured nicotine in the air of the living rooms in smoking and non-smoking households with a passive sampler for a period of 2 weeks, several months after the questionnaire had been completed. Smoking habits reported in the questionnaire generally with reported number of cigarettes smoked during the measurement weeks, and with nicotine concentrations in the air. These results suggest that exposure classification based on questionnaire data is likely to be reasonably valid