Effects of air pollution and the introduction of the London Low Emission Zone on the prevalence of respiratory and allergic symptoms in schoolchildren in East London: a sequential cross-sectional study

The adverse effects of traffic-related air pollution on children’s respiratory health have been widely reported, but few studies have evaluated the impact of traffic-control policies designed to reduce urban air pollution. We assessed associations between traffic-related air pollutants and respiratory/allergic symptoms amongst 8–9 year-old schoolchildren living within the London Low Emission Zone (LEZ). Information on respiratory/allergic symptoms was obtained using a parent-completed questionnaire and linked to modelled annual air pollutant concentrations based on the residential address of each child, using a multivariable mixed effects logistic regression analysis. Exposure to traffic-related air pollutants was associated with current rhinitis: NOx (OR 1.01, 95% CI 1.00–1.02), NO2 (1.03, 1.00–1.06), PM10 (1.16, 1.04–1.28) and PM2.5 (1.38, 1.08–1.78), all per μg/m3 of pollutant, but not with other respiratory/allergic symptoms. The LEZ did not reduce ambient air pollution levels, or affect the prevalence of respiratory/allergic symptoms over the period studied. These data confirm the previous association between traffic-related air pollutant exposures and symptoms of current rhinitis. Importantly, the London LEZ has not significantly improved air quality within the city, or the respiratory health of the resident population in its first three years of operation. This highlights the need for more robust measures to reduce traffic emissions

Winter Time Concentrations and Size Distribution of Bioaerosols in Different Residential Settings in the UK

The total concentration and size distribution of bioaerosols in three different types of housing (single room in shared accommodation [type I], single bedroom flat in three-storey building [type II] and two- or threebedroom detached houses [type III]) was assessed during the winter. This research was an extension of a previous study carried out in the summer. The measurement campaign was undertaken in winter 2008 and 30 houses were sampled. Samples were taken from kitchens, living rooms, corridors (only in housing type I) and outdoors with an Anderson 6 stage viable impactor. In housing type I, the total geometric mean concentration was highest in the corridor for both bacteria and fungi (3,171 and 1,281 CFU/m3, respectively). In type II residences, both culturable bacteria and fungi were greatest in the living rooms (3,487 and 833 CFU/m3, respectively). The living rooms in type III residences had largest number of culturable bacteria (1,361 CFU/m3) while fungi were highest in kitchens (280 CFU/m3). The concentrations of culturable bacteria and fungi were greater in mouldy houses than non-mouldy houses. A considerable variation was seen in the size distribution of culturable bacteria in type I residences compared to types II and III. For all housing types more than half of culturable bacterial and fungal aerosol were respirable (<4.7 μm) and so have the potential to penetrate into lower respiratory system. Considerable variation in concentration and size distribution within different housing types in the same geographical region highlights the impact of differences in design, construction, use and management of residential built environment on bioaerosols levels and consequent varied risk of population exposure to airborne biological agents. © Springer Science+Business Media B.V. 2012

Indoor allergens in settled dust from kindergartens in city of Łódź, Poland

Objectives: The main objective of the study was to determine the levels of house dust mite (Der p1), dog (Can f1), cat (Fel d1) and cockroach (Bla g2) allergens in kindergartens localized in an urban agglomeration. Material and Methods: A quantitative analysis of allergens was carried out in settled dust samples collected by vacuuming the floor surface in three kindergartens (N = 84) and children's clothing (N = 36). The samples were collected in springsummer and autumn-winter periods as well as at the beginning and end of the week. The allergen dust concentration was determined by enzyme-linked immunoenzymatic assay (ELISA). Results: The mean geometric concentrations (±geometric standard deviations) of allergens Der p1, Can f1, Fel d1 and Bla g2 determined in kindergartens were: 0.02±3.21 μg/g of dust; 0.97±4.49 μg/g of dust; 0.30±4.43 μg/g of dust and 0.01±3.08 μg/g of dust, respectively. Younger classrooms (children aged from 3 to 4 years) were characterized by almost twice higher mean concentration of allergen Fel d1, as compared to older classrooms (children aged from 5 to 6 years) (p < 0.05). A significant impact of seasonality on the level of dog allergen Can f1 was found (p < 0.05). No significant weekly variation was found in average concentrations of the allergens. Children who had a dog and/or cat at home were characterized by high concentrations of allergens Can f1 and Fel d1 on their clothes (59.2±5.39 μg Can f1/g of dust; 3.63±1.47 μg Fel d1/g of dust), significantly higher than concentrations of allergens in children who did not have any pets (p < 0.001). Conclusions: Special attention should be paid to keeping the kindergarten rooms tidy and clean and to an appropriate choice of furnishings and fittings which would prevent the proliferation of the house dust mite and accumulation of allergens

Impact of residential building regulations on reducing indoor exposures to outdoor PM2.5 in Toronto

We conducted a cost benefit analysis of residential building regulations on reducing the exposure to outdoor PM2.5 in Toronto. By combining a combined mass balanced model, a time-weighted activity exposure model, epidemiological based concentration-response, and monetary valuation method, various morbidity and mortality outcomes were estimated for different residential building scenarios. It was found that retrofitting residential buildings to comply with minimum building code regulations can save US$2.3 billion/year in health care. Citywide adoption of R2000 standard from current housing corresponds to US$3.8 billion/year. Use of mechanical HVAC systems, improved filtration (with recirculation) and tighter building envelope (lower infiltration rate) were noted as the key factors that influence PM2.5 exposure reductions and health impacts. Estimated costs of retrofitting existing homes to adopt these regulations were about 2.3-2.9 times of the health savings. Citywide use of filters with better efficiency is anticipated to lead to annual health savings significantly exceeding the capital and running costs.Peer reviewed: YesNRC publication: Ye

Development and application of a protocol to evaluate impact of duct cleaning on IAQ of office buildings

Field investigations reporting increased airborne particles concentrations after ventilation duct cleaning (DC) and emissions of biocides following its use in DC highlight a need to protect building occupants from possible exposures to these harmful pollutants. A new protocol was developed to include tests for assessing duct surface cleanliness and harmful airborne pollutant concentrations associated with DC. Two office buildings undergoing DC were chosen to demonstrate the protocol application. The new protocol was tested for surface cleanliness assessment using a combination of visual inspection and a vacuum test method wherever possible. For airborne pollutant concentration assessments, indoor air exposures to total particle, fungi and VOCs were measured. The test application demonstrates that it is possible to determine harmful airborne pollutant concentration levels attributed to DC activities while still maintaining industrial performance standards of surface cleanliness.Peer reviewed: YesNRC publication: Ye