Exposure to formaldehyde and asthma outcomes: A systematic review, meta-analysis, and economic assessment.

BACKGROUND: Every major federal regulation in the United States requires an economic analysis estimating its benefits and costs. Benefit-cost analyses related to regulations on formaldehyde exposure have not included asthma in part due to lack of clarity in the strength of the evidence. OBJECTIVES: 1) To conduct a systematic review of evidence regarding human exposure to formaldehyde and diagnosis, signs, symptoms, exacerbations, or other measures of asthma in humans; and 2) quantify the annual economic benefit for decreases in formaldehyde exposure. METHODS: We developed and registered a protocol in PROSPERO (Record ID #38766, CRD 42016038766). We conducted a comprehensive search of articles published up to April 1, 2020. We evaluated potential risk of bias for included studies, identified a subset of studies to combine in a meta-analysis, and rated the overall quality and strength of the evidence. We quantified economics benefit to children from a decrease in formaldehyde exposure using assumptions consistent with EPA's proposed formaldehyde rule. RESULTS: We screened 4,821 total references and identified 150 human studies that met inclusion criteria; of these, we focused on 90 studies reporting asthma status of all participants with quantified measures of formaldehyde directly relevant to our study question. Ten studies were combinable in a meta-analysis for childhood asthma diagnosis and five combinable for exacerbation of childhood asthma (wheezing and shortness of breath). Studies had low to probably-low risk of bias across most domains. A 10-µg/m3 increase in formaldehyde exposure was associated with increased childhood asthma diagnosis (OR = 1.20, 95% CI: [1.02, 1.41]). We also found a positive association with exacerbation of childhood asthma (OR = 1.08, 95% CI: [0.92, 1.28]). The overall quality and strength of the evidence was rated as "moderate" quality and "sufficient" for asthma diagnosis and asthma symptom exacerbation in both children and adults. We estimated that EPA's proposed rule on pressed wood products would result in 2,805 fewer asthma cases and total economic benefit of $210 million annually. CONCLUSION: We concluded there was "sufficient evidence of toxicity" for associations between exposure to formaldehyde and asthma diagnosis and asthma symptoms in both children and adults. Our research documented that when exposures are ubiquitous, excluding health outcomes from benefit-cost analysis can underestimate the true benefits to health from environmental regulations.

A comparison of the contrast stains, Chicago blue, chlorazole black, and Parker ink, for the rapid diagnosis of skin and nail infections.

BACKGROUND: The cheapest, most rapid method for the diagnosis of mycotic skin and nail infections is direct examination of samples using a KOH preparation. The standard KOH wet mount lacks a color contrast. Various contrast dyes are available. Parker ink is one which has been extensively used, however in recent times the stain no longer provides a suitable color contrast. Two other dyes that are available are Chicago blue and chlorazole black. METHODS: 100 samples of skin or nails were prospectively examined using Chicago blue, chlorazole black, and Parker ink-KOH stains. The samples were also cultured, with culture being the diagnostic gold standard. RESULTS: The sensitivities and specificities of the Chicago blue, chlorazole black and Parker ink stains were 78% & 96%; 63% & 97%; and 48% and 96%, respectively. CONCLUSION: The Chicago blue-KOH stain provides a good color contrast and is a suitable replacement for the Parker ink-KOH stain. It is suitable for use in the dermatologist's office or in the laboratory.

Formaldehyde in China: production, consumption, exposure levels, and health effects.

Formaldehyde, an economically important chemical, is classified as a human carcinogen that causes nasopharyngeal cancer and probably leukemia. As China is the largest producer and consumer of formaldehyde in the world, the Chinese population is potentially at increased risk for cancer and other associated health effects. In this paper we review formaldehyde production, consumption, exposure, and health effects in China. We collected and analyzed over 200 Chinese and English documents from scientific journals, selected newspapers, government publications, and websites pertaining to formaldehyde and its subsequent health effects. Over the last 20 years, China's formaldehyde industry has experienced unprecedented growth, and now produces and consumes one-third of the world's formaldehyde. More than 65% of the Chinese formaldehyde output is used to produce resins mainly found in wood products - the major source of indoor pollution in China. Although the Chinese government has issued a series of standards to regulate formaldehyde exposure, concentrations in homes, office buildings, workshops, public places, and food often exceed the national standards. In addition, there have been numerous reports of formaldehyde-induced health problems, including poisoning and cancer. The lack of quality epidemiological studies and basic data on exposed populations emphasizes the need for more extensive studies on formaldehyde and its related health effects in China.

Early operative intervention versus conventional treatment in epistaxis: randomized prospective trial.

OBJECTIVE: This prospective randomized trial was designed to compare intranasal endoscopic sphenopalatine artery ligation (ESAL) with conventional nasal packing in the treatment of recurrent epistaxis. METHODS: Patients were registered in the study databank following referral for epistaxis control to the otolaryngology service at the University of Alberta. All patients were initially packed using Merocel (Xomed Surgical Products, Jacksonville, FL) nasal dressings bilaterally. Patients were enrolled in the study following failure of Merocel packings. Informed consent was obtained in accordance with the Health Research Ethics Board. The patients were then managed with Vaseline nasal packs or ESAL. Patient demographics, treatment characteristics, number of hospitalization days, and rates of recurrence were recorded prospectively. The total cost of treatment for each patient was calculated. RESULTS: Nineteen patients were enrolled in the study. There was a significant reduction in cost and length of hospitalization of the patients undergoing ESAL compared with the conventional nasal packings. ESAL was also 89% effective in controlling the bleeding and had minimal sequelae or complications. The overall calculated cost of patients undergoing ESAL was dollars 5133 compared with dollars 12213 in the conservative group, resulting in an average saving of dollars 7080 per patient. There was overwhelming patient satisfaction with ESAL compared with nasal packings. CONCLUSION: ESAL is an excellent, well-tolerated, and cost-effective method of treating recurrent epistaxis.