HEPA filtration improves asthma control in children exposed to traffic‐related airborne particles

Abstract

Traffic‐related airborne particles are associated with asthma morbidity. The aim of this study was to assess the impact of a high‐efficiency particulate air (HEPA) filtration on the concentrations of traffic particles and the resultant effect on children with asthma. Forty‐three children with asthma were enrolled in this double‐blind, placebo‐controlled crossover design. A HEPA air cleaner or a placebo “dummy” was placed in participants’ homes for four weeks, interrupted by a one‐month washout period, before crossing over to the other treatment arm for four weeks. Air sampling and health outcomes, including asthma control (ACQ) and quality of life (AQLQ) measures, were completed prior to and at the end of each treatment arm. Indoor concentrations of traffic particles were significantly reduced with the HEPA treatment but not with the “dummy” treatment. In participants with poorly controlled asthma and lower quality of life at baseline, ACQ and AQLQ scores were significantly improved (1.3 to 0.9, P = .003 and 4.9 to 5.5, P = .02, respectively) following the HEPA treatment. In this study, HEPA filtration is associated with improved clinical outcomes and quality of life measures in children with uncontrolled asthma.

Negative ions offset cardiorespiratory benefits of PM 2.5 reduction from residential use of negative ion air purifiers

“…Our results indicate that NIAPs reduced indoor PM 2.5 levels by 75% (from 29.5 under sham NIAP to 7.5 µg/m 3 under true NIAP). This efficiency of PM 2.5 removal was comparable to those achieved by HEPA‐based or ESP‐based air purifiers 6‐12,25,26 …”

“…Previous studies have shown that high‐efficiency particulate air (HEPA) purifiers were effective in reducing indoor PM levels and improving occupants’ cardiopulmonary health 6‐12 . However, the effectiveness of HEPA purifiers relies on regular replacement of filters, which could be costly and time‐consuming.…”

Assessing Impact of Household Intervention on Indoor Air Quality and Health of Children with Asthma in the US-Mexico Border: A Pilot Study

“…Our study has several limitations. Firstly, the total study period, including pre-and postintervention periods, was 15 days so that it might be a shorter time to see substantial changes in indoor air condition and participants' health outcomes when compared with other similar studies that had at least 4 weeks [40,45]. However, we observed a 12% significant reduction in the mean PM 2.5 level and some positive outcomes in children with asthma, providing a promising basis for future studies.…”

“…This result is consistent with the findings of other intervention studies using HEPA filtration. A study found that indoor PM 2.5 level was reduced from 7.6 μ g/m 3 to 3.4 μ g/m 3 after the HEPA intervention [ 39 ], and another study also reported a significant reduction in PM 2.5 level from 8.0 μ g/m 3 to 4.8 μ g/m 3 with the use of HEPA [ 40 ].…”

“…Fourth, due to the small sample size, we could not use the statistical model to adjust the characteristics of socioeconomic status, which may affect asthma severity. Given that similar studies included more than 40 participants [ 39 , 40 , 45 ], the future study should have more sample sizes to obtain better results by conducting a statistical analysis. However, the socioeconomic status of participating families in this study is homogeneous as low-education and low-income Hispanic population supported by public health insurance aid was recruited.…”