High-Efficiency Particulate Air Filters for Preventing Wildfire-related Asthma Complications: A Cost-Effectiveness Study.

Rationale: Air pollution caused by wildfire smoke is linked to adverse health outcomes, especially for people living with asthma. Objectives: To evaluate whether government rebates for high-efficiency particulate air (HEPA) filters, which reduce concentrations of smoke particles indoors, are cost effective in managing asthma and preventing exacerbations in British Columbia (BC), Canada. Methods: We used a Markov model to analyze health states for asthma control, exacerbation severity, and death over a retrospective time horizon of 5 years (2018-2022). Concentrations of wildfire smoke-derived particulate matter with an aerodynamic diameter ⩽2.5 µm (PM2.5) from the Canadian Optimized Statistical Smoke Exposure Model and relevant literature informed the model. The base-case analysis assumed continuous use of a HEPA filter. Costs and quality-adjusted life-years (QALYs) resulting from varying rebates were computed for each Health Service Delivery Area (HSDA). Measurements and Main Results: In the base-case analysis, HEPA filter use resulted in increased costs of $83.34 (SE, $1.03) and increased QALYs of 0.0011 (SE, 0.0001) per person. The average incremental cost-effectiveness ratio among BC HSDAs was $74,652/QALY (SE, $3,517), with incremental cost-effectiveness ratios ranging from $40,509 to $89,206 per QALY in HSDAs. Across the province, the intervention was projected to prevent 4,418 exacerbations requiring systemic corticosteroids, 643 emergency department visits, and 425 hospitalizations during the 5-year time horizon. A full rebate was cost effective in 1 of the 16 HSDAs across BC. The probability of cost-effectiveness ranged from 0.1% to 74.8% across HSDAs. A $100 rebate was cost effective in most HSDAs. Conclusions: The cost-effectiveness of HEPA filters in managing wildfire smoke-related asthma issues in BC varies by region. Government rebates up to two-thirds of the filter cost are generally cost effective, with a full rebate being cost effective only in Kootenay Boundary.

Dead in the air- The need to adapt to CoVID adaptations.

During the recent CoVID-19 pandemic, airway management recommendations have been provided to decrease aerosolization and risk of viral spread to healthcare providers. High efficiency particulate air (HEPA) viral filters and adaptors are one way to decrease the risk of aerosolization during intubation. When placed proximal to the ventilator circuit, these viral filters and adaptors can create a significant amount of dead space, which in our smallest patients can significantly impact effective ventilation. We report a case of hypoventilation in a pediatric patient due to lack of provider team appreciation or ventilator sensing of additional dead space due to HEPA viral filter and adaptor.

Prevention of exposure to and spread of COVID-19 using air purifiers: challenges and concerns.

Coronavirus disease 2019 (COVID-19) is now a pandemic. The Korean government has declared a red alert, which is the highest level of the national infectious disease alert system, and the World Health Organization has similarly declared its highest-level pandemic alert (phase 6). The spread of COVID-19 is an unprecedented worldwide public health problem that governments and individuals must work to overcome. Recently, an infection cluster arose in a call center in Seoul. To support call center companies, the Korean Ministry of Employment and Labor has proposed covering the costs of installing partitions and air purifiers, providing hand sanitizers, and supplying masks to prevent droplet and aerosol infections. Air purifiers are expected to be installed on the floor with the exhaust outlets at a higher level, such as the level of the desks or breathing zones of workers. When a worker coughs or releases droplets near a colleague's respiratory system, the droplets may spread throughout the call center via air flow from air purifier. In this fashion, a single infected person can give rise to an infection cluster. Attempts to prevent infection must not lead to new infections, and the installation of air purifiers may cause new problems. Therefore, using air purifiers to control the spread of COVID-19 should be approached with caution.

Misinterpretation of carbon dioxide monitoring because of deadspace of heat and moisture exchanger with a filter in pediatric anesthesia: A case report.

RATIONALE: When patients are intubated and treated with mechanical ventilation, the upper respiratory tract is bypassed by the flow of dry and cold air. To prevent disturbances of airway homeostasis, a heat and moisture exchanger filter (HMEF) has been applied to breathing circuit. PATIENT CONCERNS: A 4-month-old male infant was ventilated with the pediatric HMEF. We report the impact of ignoring the direct influence of a filter containing deadspace in pediatric mechanical ventilation. DIAGNOSES: The breathing circuit with HMEF leads to unexpected complications such as mechanical obstructions owing to respiratory secretions, bleeding, inhaled drugs, and moisture. Besides these complications, we generally ignored the deadspace as the internal volume of the filters in breathing circuit for pediatric patients. INTERVENTIONS: After we noticed the influence of filter deadspace for pediatric patient, we removed the filter for effective respiratory circulation. OUTCOMES: The operation was completed without any specific incidents and the patient's voluntary breathing was well-maintained. The patient was discharged without any other complications. LESSONS: The increase in breathing apparatus deadspace should be minimized, and the clinicians should keep in mind that HMEF can causes respiratory acidosis with hypercapnia by apparatus deadspace rebreathing, especially for infants.

Identification, characteristics and human exposure assessments of triclosan, bisphenol-A, and four commonly used organic UV filters in indoor dust collected from Shanghai, China.

Indoor dust is a very significant medium to understand human exposure of emerging contaminants. A novel and robust analytical method to measure the amounts of six personal care products (PCPs) (triclosan, bisphenol-A and four commonly used organic ultraviolet (UV) filters) simultaneously in indoor dust is developed in this paper. Target analytes were extracted using accelerated solvent extraction. After sample cleanup by solid-phase extraction (SPE), the extracts were derivatized and analyzed using gas chromatography-tandem mass spectrometry. The method detection limits achieves 0.16-0.62 pg g-1 (except for 4-methylbenzylidene camphor with 3800 pg g-1). The method was successfully applied to the analysis of 110 indoor dust samples from Shanghai, China. Results showed that the PCPs were found in most of the samples analyzed. The concentrations of the most analytes are relatively lower than those reported in USA, Japan, and European countries. The median concentration of octocrylene (OC) (1170.4 ng g-1) was found to be nearly 5-10 times higher than those of other analytes. The significantly higher concentration of ∑PCPs was observed in indoor dusts from residences than from offices (P < 0.05). The human exposure was analyzed by calculate the estimated daily intakes (EDI) of PCPs through dust ingestion for various age groups. The EDI of the target analytes for infants ranged from 0.85 to 6.18 ng kg-1 -bw day-1 and 0.07-0.49 ng kg-1 -bw day-1 for adults, respectively. This is the first study to report the doses of human exposure to UV filters in China.

Positive and negative ions by air purifier have no effects on embryo-fetal development in rats.

Air purifiers, which release positive and negative ions generated by an electric discharge into the air, have been widely used in common households. In this study, the developmental toxicity potential of the ionized air containing positive and negative ions was evaluated in SD rats [Crl:CD(SD)] following whole-body inhalation to obtain preliminary information for the definitive study. Two groups of 10 pregnant female rats were exposed to the ionized air at concentrations of 0 and 7,000,000 ions/cm(3) for 6 hr per day from Days 6 to 19 of gestation. All dams underwent a cesarean section on Day 20 of gestation and their fetuses were examined externally, viscerally, and skeletally for morphological changes. The ionized air had no effects on dams in terms of clinical signs, body weight, food consumption, gravid uterine weights, corrected body weight by gravid uterine weight, or necropsy findings. In addition, there were no effects on the maintenance of pregnancy, including abortion or premature delivery. No exposure-related changes were detected in the number of corpora lutea, implantations, dead embryos, or live fetuses, implantation loss, live fetal weights, sex ratio, or placental weight or features. Fetal examination revealed no external, visceral, or skeletal anomalies or variations caused by the ionized air, nor were there any changes in degree of ossification. Although this study did not fully adhere to the current guidelines because of a smaller number of animals per group, it was suggested that the ionized air has no maternal toxicity or embryo-fetal toxicity in rats.