Use Of Air Cleaners Research Articles

Use of Humidifiers with Children Suffering from Atopic Dermatitis

DEAR EDITOR Following the recent press release regarding the toxicity of the biocides mixed in the water of humidifiers as a cause of fatal pulmonary syndrome among pregnant women and young children in Korea [1], the use of humidifiers has became a public concern. There are few reports, however, on the use of humidifiers with children suffering from atopic dermatitis. Those children use humidifiers more frequently than healthy individuals, because their symptoms largely depend on the humidity in the environment, especially during winter in Korea. Therefore, they might be a risk group who are exposed to the biocides in the humidifiers. Parents of atopic dermatitis patients are more aware of controlling the relative humidity in the household environment. It is important to know how many of the children with atopic dermatitis have been exposed to humidifiers during their periods of illness, because they are more sensitive to environmental changes. We have reviewed the children's environmental health status questionnaire used in the Environmental Health Center for Atopic Diseases in the Samsung Medical Center. When children with atopic dermatitis visited the clinic, it was recommended that their parents complete the questionnaire on the children's environment, including housing, home environment, use of a humidifier, and use of pesticides and chemicals at home, etc. Although the exact time period of reference is not clarified, it can be supposed to reflect the usage at the time of survey. Because of unbalanced distribution across the year, the proportion of humidifiers used is presented on a seasonal basis. Among 375 subjects aged between 3 and 12 (218 boys and 157 girls), 179 (54.3%) children used a humidifier, while 106 (34.5%) children used an air cleaner at home. Compared to a survey on the general population (37.2%) [2] and pregnant mothers (27.6%) [3], atopic children's use of humidifiers was more popular than those population groups. There was a strong seasonal difference. Unlike the usage in the general population [2], the season with the highest usage of humidifiers in patients with atopic dermatitis was spring, followed by fall (Table 1). Use of air cleaners was also highest in spring, but was similar across the other three seasons. Table 1 Usage of humidifiers and air cleaners in houses of children with atopic dermatitis Although the study population was not representative and use of biocides was not included in the questionnaire, this result may be used to estimate the hazard of humidifier use in children with atopic dermatitis. This report shows that atopic children are exposed to humidifier aerosols much more than the general population. Parents need to be alert about the potential risk of inhaling undesirable components such as endotoxin and minerals that can be included in the water used in humidifiers.

Low-Carbon Housings and Indoor Air Quality

The purpose of this paper is to provide a review of the background information regarding low-carbon housings in the United Kingdom and to raise the concern of the possible high indoor pollution load due to the emissions from building materials and combustion products which would adversely affect the indoor air quality in air-tight buildings, especially homes. The standard guidelines given by the Building Regulations in the UK are reviewed especially in relation to mechanical ventilation with heat recovery systems. Also research literatures in relation to heat recovery ventilators and the use of air-cleaners from Korea, Hong Kong and China and from Europe are also included to illustrate the various possibilities to conserve energy and to achieve adequate ventilation with an improvement of indoor air quality. The effectiveness of using a heat recovery ventilator system and trickle ventilators in unoccupied super-energy-efficient test houses is illustrated by reviewing the long-term indoor volatile organic compound (VOC) concentrations in these test houses. The awareness of the issue is important for the future design and indoor air management of buildings, so as to provide adequate ventilation for living spaces without costing too much on energy efficiency.

A Randomized Trial of Air Cleaners and a Health Coach to Improve Indoor Air Quality for Inner-City Children With Asthma and Secondhand Smoke Exposure

To test an air cleaner and health coach intervention to reduce secondhand smoke exposure compared with air cleaners alone or no air cleaners in reducing particulate matter (PM), air nicotine, and urine cotinine concentrations and increasing symptom-free days in children with asthma residing with a smoker. Randomized controlled trial, with randomization embedded in study database. The Johns Hopkins Hospital Children's Center and homes of children. Children with asthma, residing with a smoker, randomly assigned to interventions consisting of air cleaners only (n = 41), air cleaners plus a health coach (n = 41), or delayed air cleaner (control) (n = 44). Changes in PM, air nicotine, and urine cotinine concentrations and symptom-free days during the 6-month study. The overall follow-up rate was high (91.3%). Changes in mean fine and coarse PM (PM(2.5) and PM(2.5-10)) concentrations (baseline to 6 months) were significantly lower in both air cleaner groups compared with the control group (mean differences for PM(2.5) concentrations: control, 3.5 μg/m(3); air cleaner only, -19.9 μg/m(3); and air cleaner plus health coach, -16.1 μg/m(3); P = .003; and PM(2.5-10) concentrations: control, 2.4 μg/m(3); air cleaner only, -8.7 μg/m(3); and air cleaner plus health coach, -10.6 μg/m(3); P = .02). No differences were noted in air nicotine or urine cotinine concentrations. The health coach provided no additional reduction in PM concentrations. Symptom-free days were significantly increased [corrected] in both air cleaner groups compared with the control group (P = .03). Although the use of air cleaners can result in a significant reduction in indoor PM concentrations and a significant increase in symptom-free days, it is not enough to prevent exposure to secondhand smoke.

White blood cell DNA adducts in a cohort of asthmatic children exposed to environmental tobacco smoke

PurposeExposure to environmental tobacco smoke (ETS) leads to molecular damage in the form of DNA adducts. While lung cancer risk is higher among African Americans compared to White Americans, a few studies have tested for racial differences in DNA adducts among children exposed to ETS. The purpose of this study was to test whether African American children have higher DNA adducts levels compared to White children adjusted for ETS exposure.MethodsData and biologic specimens were drawn from an existing cohort of 212 asthmatic children. These subjects participated in a 12-month ETS-reduction trial that employed HEPA air cleaners with active filter cartridges and sham filter cartridges. White blood cell (WBC) DNA was analyzed for DNA adducts using 32P-postlabeling. We assessed ETS exposure using a validated air nicotine dosimeter. We determined the independent relationship between African American race and DNA adduct levels adjusted for ETS exposure and air cleaner use.ResultsThe mean age of the subjects was 8.4 years; 55% were African American. There was no difference in DNA adduct levels between African American and White children (11.8 vs. 11.2 adducts per 109 nucleotides, p = 0.86), despite slightly higher levels of air nicotine exposure (3.4 vs. 2.2 μg/m3, p = 0.14). African American children used their air cleaners less often than White children. We found that the best predictor of DNA adduct levels was the duration of air cleaner use (r = −0.133, p = 0.056). This association was independent of cartridge type.ConclusionsWe did not see differences in adduct levels by race even after accounting for the level of ETS exposure. However, there was a marginal inverse association between air cleaner use and adducts. Additional research is required to understand this phenomenon.

Infiltration of forest fire and residential wood smoke: an evaluation of air cleaner effectiveness

Communities impacted by fine-particle air pollution (particles with an aerodynamic diameter less than 2.5 microm; PM(2.5)) from forest fires and residential wood burning require effective, evidence-based exposure-reduction strategies. Public health recommendations during smoke episodes typically include advising community members to remain indoors and the use of air cleaners, yet little information is available on the effectiveness of these measures. Our study attempted to address the following objectives: to measure indoor infiltration factor (F(inf)) of PM(2.5) from forest fires/wood smoke, to determine the effectiveness of high-efficiency particulate air (HEPA) filter air cleaners in reducing indoor PM(2.5), and to analyze the home determinants of F(inf) and air cleaner effectiveness (ACE). We collected indoor/outdoor 1-min PM(2.5) averages and 48-h outdoor PM(2.5) filter samples for 21 winter and 17 summer homes impacted by wood burning and forest fire smoke, respectively, during 2004-2005. A portable HEPA filter air cleaner was operated indoors with the filter removed for one of two sampling days. Particle F(inf) and ACE were calculated for each home using a recursive model. We found mean F(inf)+/-SD was 0.27+/-0.18 and 0.61+/-0.27 in winter (n=19) and summer (n=13), respectively, for days when HEPA filters were not used. Lower F(inf)+/-SD values of 0.10+/-0.08 and 0.19+/-0.20 were found on corresponding days when HEPA filters were in place. Mean+/-SD ACE ([F(inf) without filter-F(inf) with filter]/F(inf) without filter) in winter and summer were 55+/-38% and 65+/-35%, respectively. Number of windows and season predicted F(inf) (P<0.001). No significant predictors of ACE were identified. Our findings show that remaining indoors combined with use of air cleaner can effectively reduce PM(2.5) exposure during forest fires and residential wood burning.

Infiltration of Forest Fire and Wood Smoke: An Intervention Study to Assess Air Cleaner Effectiveness

P-289 Introduction: Forest fires and residential wood-burning are significant sources of air pollution. PM2.5 from these sources has been linked to adverse health effects. Consequently, exposed populations should be provided with evidence-based recommendations on exposure reduction. Recommendations typically include remaining indoors and use of air cleaners, yet little information is available on PM infiltration during smoke episodes or on effectiveness of air cleaners in reducing indoor concentrations. Specific research objectives of this study were to measure indoor infiltration of outdoor PM2.5 from forest fires/residential wood-smoke and to determine effectiveness of High Efficiency Particulate Air (HEPA) filter air cleaners in reducing indoor PM2.5. Methods: Indoor and outdoor PM2.5 sampling was conducted over a 48-hour period in 21 homes during winter and in 16 homes during summer. Winter sampling was conducted in 2004 in a northern Canadian community affected by residential wood-burning. Summer sampling was conducted in 2004 and 2005 in southern British Columbia, Canada in communities impacted by forest fire smoke. Continuous 1-minute averages using a light-scattering device (personal DataRAM) and integrated 48-hour filter samples (Harvard Impactor) of PM were collected for each home. A portable HEPA filter air cleaner was operated indoors during the entire sampling period, however the filter was removed for 1 of the 2 days. Infiltration factors (Finf) were calculated using a recursive model (Switzer and Ott. 2001) after removal of indoor-generated PM2.5 data using censoring algorithms (Allen et al. 2003). Results: Valid 48 hour samples were obtained from 19 homes in winter and 12 homes in summer. Average wintertime PM2.5 concentrations were 14.2ug/m3 and 35.6ug/m3 for indoor and outdoor measurements respectively. Average summer concentrations were 12.3ug/m3 and 29.2ug/m3 for indoor and outdoor measurements respectively. For days when the filter was not used, mean Finf± SD values of 0.29±0.20 and 0.53±0.32 were found for winter and summer homes respectively. On days with filter use, Finf± SD was lower in both seasons with values of 0.11±0.10 and 0.22±0.24 for winter and summer respectively. Mean± SD air cleaner efficiencies ([Finf without filter - Finf with filter]/ Finf without filter) in summer and winter were 74±40% and 49±41% respectively. Effects of housing characteristics on infiltration and air cleaner efficiency based on multivariate models will also be presented. Discussion and Conclusions: For exposures to wood and forest fire smoke, infiltration was higher in summer versus winter and in both seasons air cleaners were effective in lowering Finf.

What Is an Effective Portable Air Cleaning Device? A Review

The use of portable air cleaning devices in residential settings has been steadily growing over the last 10 years. Three out of every 10 households now contain a portable air cleaning device. This increased use of air cleaners is accompanied by, if not influenced by, a fundamental belief by consumers that the air cleaners are providing an improved indoor air environment. However, there is a wide variation in the performance of air cleaners that is dependent on the specific air cleaner design and various indoor factors. The most widely used method in the United States to assess the performance of new air cleaners is the procedure described in the American National Standards Institute (ANSI)/Association of Home Appliance Manufacturers (AHAM) AC-1-2002. This method describes both the test conditions and the testing protocol. The protocol yields a performance metric that is based on the measured decay rate of contaminant concentrations with the air cleaner operating compared with the measured decay rate with the air cleaner turned off. The resulting metric, the clean air delivery rate (CADR), permits both an intercomparison of performance among various air cleaners and a comparison of air cleaner operation to other contaminant removal processes. In this article, we comment on the testing process, discuss its applicability to various contaminants, and evaluate the resulting performance metrics for effective air cleaning.

Air filtration units in homes with cats: can they reduce personal exposure to cat allergen?

Domestic air filtration units have previously been shown to cause a dramatic fall in airborne pet allergen levels in homes with pets. Clinical trials of air filtration units, however, have failed to reveal a significant beneficial effect. Personal pet allergen exposure during air filtration unit use has never been measured. To determine the effect of air filtration on inhaled cat allergen exposure in homes with cats. Nasal air samplers were worn to measure personal cat allergen exposure. The study was carried out in five homes with cats on 4 separate days examining four experimental conditions (cat absent or present, air filtration off or on). The two operators collected four baseline samples and two 15-min samples/h over three consecutive hours. Cat allergen-bearing particles were detected by immunoblotting and allergen concentrations measured by amplified enzyme-linked immunosorbent assay (ELISA). There was a significant reduction in the quantity of the inhaled Fel d 1 when the air cleaner was used with the cat in the room. Fel d 1 halo counts (detransformed means) were 29.3 at baseline, 11.8 after 1 h, 10.0 after 2 h and 14.1 after 3 h, with no change on control days (P = 1.00). With the cat elsewhere in the house, a marginal, but statistically significant reduction was observed only after 3 h with the use of air cleaner (Fel d 1 halo count: baseline 12.4; 3 h 5.5; P = 0.01). The use of air filtration units appears to result in a much smaller reduction of inhaled cat allergen exposure than suggested by previous studies using standard air samplers. Cat removal remains the best advice to cat-allergic patients who experience symptoms upon exposure.

Air filtration devices in the control of indoor allergens.

There are a variety of air cleaning devices that have been developed for the control of indoor allergens and irritants. These include both portable, room-sized units, and central units for use with a home's heating and ventilation system. While air cleaners can help to reduce some allergens, such as those produced by cats and dogs, they are unlikely to work for most other indoor allergens. The use of air cleaners for the management of allergic disease is reviewed in this article, and specific recommendations for their use are provided.

Avoidance of allergens and air pollutants in respiratory allergy

Avoidance of allergens and air pollutants in respiratory allergy

New units for indoor air quality: decicarbdiox and decitvoc.

Two new units are proposed for the evaluation of indoor air quality using the decibel concept, which give a much better approximation of the human perception of odour intensity, compared to the CO2 and total volatile organic compounds (TVOC) concentration scales: the decicarbdiox and the devitvoc. On the psychophysical scale according to Yaglou, the weakest odour that can be detected by the human smell sensors is equal to one, and corresponds to the lower limit of percentage dissatisfaction (PD) of 5.8%. It is equivalent to: (1) a CO2 threshold concentration of 485 ppm-0 dB (odour CO2)-0 dCd (decicarbdiox), and (2) a TVOC threshold concentration of 50 micrograms m-3-0 dB (odour TVOC)-0 dTv (decitvoc). The upper limit is determined by the initial value of toxicity: (1) CO2-15,000 ppm-134 dCd, and (2) TVOC-25,000 g/m-3-135 dTv. Optimal pollutant values (corresponding to PD = 20%) and admissible values (PD = 30%) for unadapted and adapted persons are calculated. Long-term tolerable values (determining the sick building syndrome range) and short-term tolerable values (the beginning of the toxic range) are also stated. The same system used to evaluate noise can be used to evaluate air quality. Additionally, the contribution of the individual constituents (at present acoustic and odour) to the overall quality of the environment can be ascertained. The new units dCd and dTv can express an increase or decrease in air contamination, e.g. by the use of air cleaners, new building materials etc. The proposed system of using dCd and dTv is compatible with BSR/ASHRAE 62-1989 R which can be used to determine the required volume of fresh air for ventilation by an improved method, which takes into account different levels of required indoor air quality.

The Effects of an Air Cleaner in the Homes of Children With Perennial Allergic Rhinitis

Ninety children (age 4–14 years) with perennial allergic rhinitis were surveyed to determine the effect of an air cleaner in their bedroom on their allergic symptoms and on the quality of their lives. All of the children had symptoms for more than 2 years and were sensitive to multiple mold allergens. Multiple medications had not controlled the symptoms effectively. During the 12 months of the study, the children and their parents kept weekly records of the severity of symptoms. Changes in each child's quality of life were assessed through interviews with the mothers. Comparison of these records with those kept before the use of air cleaners indicated marked improvement on many different fronts when the air cleaners were in use. First, the children slept better, behaved better, and tended to be more cheerful. Second, there was significant improvement in allergic symptoms, such as sneezing, scratchy throat, nasal congestion, coughing, wheezing, infection rate of URI, and postnasal drip. Third, in terms of quality of life, there was a reduction in the number of visits to the emergency room or allergy clinic, the number of workdays missed by the parents, and the number of schooldays missed by the child as a result of the child's allergies. Fourth, the parents' expense for allergy medications decreased dramatically. Finally, the children scored somewhat better on rhinometer tests when the air cleaners were in use than when they were not. We speculate that these improvements may have resulted because the air cleaners removed mold from the air. We conclude that monitoring patients closely while they use the air cleaner provides physicians with a valuable opportunity to teach parents and their children with mold allergy about home environmental control.