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.
There are few studies on associations between airborne microbial exposure, formaldehyde, plasticizers in dwellings and the symptoms compatible with the sick building syndrome (SBS). As a follow-up of the European Community Respiratory Health Survey (ECRHS II), indoor measurements were performed in homes in three North European cities. The aim was to examine whether volatile organic compounds of possible microbial origin (MVOCs), and airborne levels of bacteria, molds, formaldehyde, and two plasticizers in dwellings were associated with the prevalence of SBS, and to study associations between MVOCs and reports on dampness and mold. The study included homes from three centers included in ECRHS II. A total of 159 adults (57% females) participated (19% from Reykjavik, 40% from Uppsala, and 41% from Tartu). A random sample and additional homes with a history of dampness were included. Exposure measurements were performed in the 159 homes of the participants. MVOCs were analyzed by GCMS with selective ion monitoring (SIM). Symptoms were reported in a standardized questionnaire. Associations were analyzed by multiple logistic regression. In total 30.8% reported any SBS (20% mucosal, 10% general, and 8% dermal symptoms) and 41% of the homes had a history of dampness and molds There were positive associations between any SBS and levels of 2-pentanol (P=0.002), 2-hexanone (P=0.0002), 2-pentylfuran (P=0.009), 1-octen-3-ol (P=0.002), formaldehyde (P=0.05), and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (Texanol) (P=0.05). 1-octen-3-ol (P=0.009) and 3-methylfuran (P=0.002) were associated with mucosal symptoms. In dwellings with dampness and molds, the levels of total bacteria (P=0.02), total mold (P=0.04), viable mold (P=0.02), 3-methylfuran (P=0.008) and ethyl-isobutyrate (P=0.02) were higher. In conclusion, some MVOCs like 1-octen-3-ol, formaldehyde and the plasticizer Texanol, may be a risk factor for sick building syndrome. Moreover, concentrations of airborne molds, bacteria and some other MVOCs were slightly higher in homes with reported dampness and mold.
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.
Institut for Folkesundhedsvidenskab, Afdeling for Miljø og Sundhed, Det Sundhedsvidenskabelige Fakultet, Københavns Universitet, Øster Farimagsgade 5, DK-1014 København K, Denmark. email@example.com
Air quality, health and climate change are closely connected. Ozone depends on temperature and the greenhouse gas methane from cattle and biomass. Pollen presence depends on temperature and CO2. The effect of climate change on particulate air pollution is complex, but the likely net effect is greater health risks. Reduction of greenhouse-gas emissions by reduced livestock production and use of combustion for energy production, transport and heating will also improve air quality. Energy savings in buildings and use of CO2 neutral fuels should not deteriorate indoor and outdoor air quality.
Allergy to indoor allergens can cause frequent and severe health problems in children. Because little is known about the content of allergens in the indoor environments in Norway, we wanted to assess the levels of cat, dog and mite allergens in schools and day-care centers in Oslo. Allergen levels in dust samples from 155 classrooms and 81 day-care units were measured using commercially available enzyme-linked immunosorbent assay (ELISA) kits. Additionally, we measured the levels of endotoxin in 31 day-care units, using the limulus amebocyte lysate test. Most of the dust samples contained detectable amounts of cat and dog allergens. In mattress and floor dust (day-care centers), and curtain and floor dust (schools) the median Fel d 1 levels were 0.17, 0.002, 0.02 and 0.079 microg/m2, while the median Can f 1 levels were 1.7, 0.03, 0.1 and 0.69 microg/m2, respectively. Levels of cat and dog allergens in school floor dust were associated with the number of pupils with animals at home. In contrast,
House dust mites are the most important indoor allergens in our region. During recent years more dwellings have become infested, most likely as a result of increased indoor humidity due to reduced ventilation. Among Danish adults, 14% have developed IgE against mites. The allergens are stable and can remain for years. Keeping the humidity low ( 55 degrees C mites are killed and allergens removed. In addition mattress covers seem to be useful, although guidelines for quality assessment are lacking. Reduction in mite exposure will reduce development of allergy in all age groups especially in the newborn period. Immunotherapy can be offered in rhinitis and moderate asthma when sufficient allergen reduction cannot be accomplished.
The aims of the study were to evaluate if the front-door concentrations of benzene, toluene, and xylenes can be used to classify the personal exposures of Danish children and to identify factors that affect their personal exposure. Average concentrations were measured over 1 week with diffusive samplers, and the personal exposures of 98 children and the concentrations outside the front doors of their homes were measured simultaneously. Time and activity patterns were noted in diaries. The front-door concentrations were significantly higher in Copenhagen than in rural areas (all P
This study was conducted in a school center that had been the focus of intense public concern over 2 years because of suspected mold and health problems. Because several attempts to find solutions to the problem within the community were not satisfactory, outside specialists were needed for support in solving the problem. The study group consisted of experts in civil engineering, indoor mycology, and epidemiology. The studies were conducted in close cooperation with the city administration. Structures at risk were opened, moisture and temperature were measured, and the causes of damage were analyzed. Microbial samples were taken from the air, surfaces, and materials. Health questionnaires were sent to the schoolchildren and personnel. Information on the measurements and their results was released regularly to school employees, students and their parents, and to the media. Repairs were designed on the basis of this information. Moisture damage was caused mainly by difficult moisture conditions at the building site, poor ventilation, and water leaks. Fungal genera (concentrations
Cites: Sci Total Environ. 1992 Dec 15;127(1-2):79-891480960
Epidemiologic studies of uranium miners and other underground miners have consistently shown miners exposed to high levels of radon to be at increased risk of lung cancer. More recently, concern has arisen about lung cancer risks among people exposed to lower levels of radon in homes. The current Canadian guideline for residential radon exposure was set in 1988 at 800 Bq/m(3). Because of the accumulation of a considerable body of new scientific evidence on radon lung cancer risks since that time, Health Canada sponsored a workshop to review the current state-of-the-science on radon health risks. The specific objectives of the workshop were (1) to collect and assess scientific information relevant to setting national radon policy in Canada, and (2) to gather information on social, political, and operational considerations in setting national policy. The workshop, held on 3-4 March 2004, was attended by 38 invited scientists, regulators, and other stakeholders from Canada and the United States. The presentations on the first day dealt primarily with scientific issues. The combined analysis of North American residential radon and lung cancer studies was reviewed. The analysis confirmed a small but detectable increase in lung cancer risk at residential exposure levels. Current estimates suggest that radon in homes is responsible for approximately 10% of all lung cancer deaths in Canada, making radon the second leading cause of lung cancer after tobacco smoking. This was followed by a perspective from an UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) working group on radon. There were two presentations on occupational exposures to radon and two presentations considered the possibility of radon as a causative factor for cardiovascular disease and for cancer in other organs besides the lung. The possible contribution of environmental tobacco smoke to lung cancers in nonsmokers was also considered. Areas for future research were identified. The second day was devoted to policy and operational issues. The presentations began with a perspective from the U.S. Environmental Protection Agency, followed by a history of radon policy development in Canada. Subsequent presentations dealt with the cost-effectiveness of radon mitigation, Canadian building codes and radon, and a summary of radon standards from around the world. Provincial representatives and a private consultant were given opportunities to present their viewpoints. A number of strategies for reducing residential radon exposure in Canada were recognized, including testing and mitigation of existing homes (on either a widespread or targeted basis) and changing the building code to require that radon mitigation devices be installed at the time a new home is constructed. The various elements of a comprehensive national radon policy were set forth.