BACKGROUND: The overall aim of this study was to investigate how airborne house dust particles may contribute to an allergic immune response, and thereby also to asthma and allergic diseases. MATERIAL AND METHODS: Using transmission electron microscopy, we quantified and characterized airborne house dust particles, with regard to elemental and size distribution. Furthermore, an immunogold labelling technique was used to study whether some common allergens were present on the surface of airborne house dust particles. Finally, a mouse model was used to study the adjuvant activity of airborne house dust on the IgE antibody response. RESULTS: A vast majority of the airborne particles samples from homes in Oslo were found to be less than 2.5 microns in diameter, thus they are liable to penetrate deep into the respiratory tree. This PM2.5 fraction contained, in addition to sulphur aerosols and silicates, many soot particles, most of them being less than 1 micron in diameter. These soot particles were found to carry allergens on their surface. We also found that diesel exhaust particles, which is probably a main soot component of airborne house dust, absorbed several wellknown allergens in vitro. Furthermore, the airborne house dust particles were found to elicit a local lymph node response, and to have an adjuvant activity on the production of IgE antibodies to ovalbumin as a model allergen. INTERPRETATION: These results show that indoor suspended particulate matter contains a lot of potential allergen carriers, i.e. soot particles (carbon aggregates), most of them being less that 1 micron in diameter and thereby able to transport allergens deep into the airways. In addition, our results indicate that suspended particulate matter may have an adjuvant effect on the production of IgE to common environmental allergens, and also may provoke a local inflammatory response.
The common food preparation processes, frying, broiling and baking, can give rise to air pollutants that are known to be mutagenic and carcinogenic in animal tests. A large number of persons can be exposed to such fumes as cooking is performed in most households and in many commercial enterprises. Additional studies on the emissions from these processes and exposure measurements are needed. Epidemiological studies on occupationally-exposed cooks and bakers with respect to cancer are equivocal.
Air pollution referable to increased ambient levels of sulfur dioxide and suspended particulates is associated with increased episodes of acute bronchitis and is also causally related to some cases of chronic bronchitis. Oxidant air pollution is associated with abnormalities of pulmonary function in children and is a major contributory factor in COP, especially bronchitis, in some areas of the United States. The relationship of nitrogen dioxide atmospheric contamination to COPD is still controversial. In our opinion, the epidemiologic studies conducted to date have been inadequate and further elucidation is indicated. Cadmium fumes and compounds have been found to be instrumental in the development of some cases of chronic bronchitis and emphysema in Sweden. This association is unproved in the United States and warrants a thorough clinical and epidemiologic evaluation.
BACKGROUND: Particulate air pollution has been much discussed in Norway during the last few years. Coarse particles from asphalt are likely to have quite different properties than the far smaller particles from diesel exhaust. MATERIALS AND METHODS: On the basis of data from the literature and our own research, we discuss the health problem of different types of particles with a focus on allergy and respiratory symptoms. RESULTS: Diesel exhaust particles have well-documented adverse effects in relation to allergic airway disease. They increase symptoms load in already allergic individuals and also seem to contribute to the increased prevalence of allergy. PM10 is today measured on the basis of weight, not on number. Diesel exhaust particles are much smaller than road surface particles; hence PM10 measurements reflect road surface dust pollution more than exhaust particles. INTERPRETATION: Focus should now be given to diesel exhaust particles in order to reduce the adverse health effects of particulate air pollution in Norwegian cities.
Comment In: Tidsskr Nor Laegeforen. 2002 Aug 10;122(18):176612362683
Many investigations suggest that a high degree of air-borne pollution increases the prevalence of diseases like asthma and eczema. SÃ¸r-Varanger Municipality in Finnmark County in the north of Norway receives much air-borne pollution from domestic industry and from the metallurgic industry on the Kola peninsula in North-Western Russia. We have investigated indirect parameters of morbidity caused by asthma and eczema by analyzing data on drug consumption and hospital admissions. In SÃ¸r-Varanger there is high consumption of corticosteroids for dermatological use. Consumption of anti-asthmatic drugs and number of admissions to hospital for asthma and eczema were no higher than expected. We suspect that air-borne pollution, particularly the heavy metal nickel, increases the prevalence and perhaps worsens the degree of eczema in SÃ¸r-Varanger.
The effect of airborne pollution, especially nickel, from Kola has been studied in 10,612 persons who participated in a cardiovascular screening survey in Finnmark in 1974-75. The age-range was 35-49 years and a follow-up for death was conducted up to 1985. Men living in the community of Sør-Varanger (close to the border) had a relative risk (RR) for death from diseases of 1.2 (95% confidence intervall; 0.9-1.6) compared with the rest of Finnmark, for women RR = 1.1. The increase in mortality for men was due to infactus cordis RR = 1.5 (1.0-2.4), and was not consistent for women (RR = 0.9). The study does not support the view that air pollution in this area has increased the risk of death.
The hypothesis that exposure to traffic-related air pollution increases the risk of developing cancer during childhood was investigated. The authors enrolled 1,989 children reported to the Danish Cancer Registry with a diagnosis of leukemia, tumor of the central nervous system, or malignant lymphoma during 1968-1991 and 5,506 control children selected at random from the entire childhood population. The residential histories of the children were traced from 9 months before birth until the time of diagnosis of the cases and a similar period for the controls. For each of the 18,440 identified addresses, information on traffic and the configuration of streets and buildings was collected. Average concentrations of benzene and nitrogen dioxide (indicators of traffic-related air pollution) were calculated for the relevant period, and exposures to air pollution during pregnancy and during childhood were calculated separately. The risks of leukemia, central nervous system tumors, and all selected cancers combined were not linked to exposure to benzene or nitrogen dioxide during either period. The risk of lymphomas increased by 25% (p for trend = 0.06) and 51% (p for trend = 0.05) for a doubling of the concentration of benzene and nitrogen dioxide, respectively, during the pregnancy. The association was restricted to Hodgkin's disease.