Effects of aerosols in common use on the ventilatory capacity of the lung

Sprays and diffusers as indoor air fresheners: Exposure and health risk assessment based on measurements under realistic indoor conditions

Noncombustible air fresheners are indoor air emission sources of concern. The associated health risks should be better understood. Based on 15 products (4 sprays, 6 passive diffusers, and 5 active diffusers), the health risk assessment (HRA) approach was applied to a national use survey in France and to concentrations measured in an experimental house. The targeted substances included volatile organic compounds (VOCs), carbonyls, and fine particles (PM_2.5 ). Mean-use and reasonable worst-case generic scenarios were designed. No situation of concern occurred regarding chronic exposure associated with the mean use. Under the reasonable worst-case scenarios, the chronic risk could exceed selected health reference standards, mainly for acrolein (average inhaled concentration (AIC) up to 3.5 µg/m³ ), benzene (AIC up to 4 µg/m³ ), and limonene (AIC up to 8 mg/m³ ). The acute exposure, defined as a 1-h exposure, could exceed selected health standards, primarily for acrolein (up to 23 µg/m³ ) and formaldehyde (up to approximately 370 µg/m³ ). Furthermore, the 1-h average PM_2.5 concentration, including ultrafine particles, could exceed 100 µg/m³ , typically for sprays. These results suggest that the highest exposures should be reduced and, as such, that the emissions of the highest-emissivity products should be lowered.

The development of environmentally acceptable fluorocarbons

Chlorofluorocarbons (CFCs) were introduced in the 1930s as the safe replacements for the toxic and flammable refrigerants being used at that time. Subsequently, hydrochlorofluorocarbons (HCFCs) were also developed. In addition to refrigerant applications, they were used as foam blowing agents, as solvents and as propellants for many aerosols. In the 1970s and 1980s, concern developed about their environmental impact, specifically on stratospheric ozone depletion. Industry began to consider acceptable replacements. In 1987, many of the governments of the world came together and drafted the Montreal Protocol, calling upon Industry to initially phase out production of the CFCs and later HCFCs. Within 4 months of the signing of the Montreal Protocol, the 15 global major producers joined together to form the Alternative Fluorocarbons Environmental Acceptability Study (AFEAS), which sponsored research into environmental effects and the Program for Alternative Fluorocarbons toxicity Testing, PAFT), which examined the toxicology of potential replacements for the CFCs and HCFCs. Nine replacements were identified by companies and, through this international cooperation; toxicology programs were designed, conducted, and evaluated without duplication of effort and testing; consequently these new products were introduced within less than 10 years. Indeed the Montreal Protocol has been recognized as the most appropriate international treaty to phase-down HFCs. In 2016 the Kigali Amendment to the Montreal Protocol set out a phase-down schedule for the consumption and production of HFCs. In order to reduce the consumption and emissions of high GWP HFCs. Recently lower GWP HFCs and very low GWP HFOs (hydrofluoroolefins and HCFOs (hydrochlorofluoroolefins) have been introduced into a range of applications. Summaries of the toxicology profiles of some of the original CFCs and HCFCs, the replacements and the new post-PAFT replacements are described. The chemicals in this review include CFC-11, CFC-12, CFC-113, CFC-114, HCFC 22, HCFC-123, HCFC-124, HCFC-141b, HCFC-142b, HCF-32, HFC-125, HFC-134a, HFC-143a, HFC-152a, HFC-245ea, HFC-245fa, HFO-1234yf, HFO-1234ze, and HCFO-1233zd.

Respiratory effects of organic solvent exposure

Organic solvents are widely used in industrial processes and found in many common household products. Exposures to solvents are common in both idustrialized and industrializing countries. While organic solvents exposure is well known to produce central nervous system toxicity, hepatic, renal and dermatologic injury, the respiratory effects of solvent exposure are poorly documented. Several recent population-based epidemiologic studies have found an independent association of occupational solvent exposure with respiratory symptoms, impaired pulmonary function or respiratory disease, but interpretation of these studies is limited by self-reported exposure data. Animal studies have demonstrated adverse effects in both the conducting and the respiratory airways, although often at very high exposure levels. Human chamber studies have most consistently reported irritation of the eyes, nose and throat without evidence of airway hyper-responsiveness. Case series have observed obstructive and restrictive effects in patients with high level inhalational exposures to solvents, particularly formaldehyde, but occupational epidemiologic studies have not consistently demonstrated changes in pulmonary function. Finally, mortality studied have not found increased mortality rates from respiratory disease in occupations associated with solvent use. In general, solvents have been demonstrated to cause mucosal irritation of the eyes and upper airways, but studies of pulmonary impairment following exposure have been limited and inconsistent. Solvent-mediated respiratory toxicity is biologically plausible, but further research is needed to better characterize exposures and to elucidate the specific mechanisms associated with injury.

Helium-oxygen flow-volume curves in detecting acute response to hair spray

The acute effect of hair spray on small airway function was studied in 11 healthy subjects by recording maximum expiratory flow-volume (MEFV) curves while the subjects were breathing first air (Ar) and then a 80% helium-20% oxygen mixture (He). The flow rate response of breathing He compared to Ar (delta MEF50) at 50% of the control forced vital capacity (FVC), and the point of identical flow on Ar and He MEFV curves, known as volume of isoflow (VisoV) were measured. Eight of 11 subjects reacted to the hair spray by demonstrating a decrease in the MEF50 and delta MEF50 although the difference was not significant. However, there was a significant increase in VisoV at 12,20 and 30 min post exposure. VisoV may be a sensitive index in detecting small airway dysfunction following acute exposure to hair spray.

Effects of fluorocarbon propellants on respiratory flow and ECG

Ten subjects were exposed to the propellants freon 11, freon 12, freon 114, to two mixtures of freon 11 and 12 and to a mixture of freon 12 and 114. The length of exposure was 15, 45 or 60 seconds. Maximum expiratory flow-volume (MEF) curves and ECG were recorded before, and intermittently up to 1 hour after, exposure. Breathing level concentrations of propellants during exposure were determined by gas chromatography. All freons induced biphasic reduction of ventilatory capacity on inhalation. The first fall occurred within a few minutes of exposure while the second was delayed 13-30 minutes after exposure. The effects of mixtures were greater than those of individual freons. The relative fall in MEF 75% was more pronounced than that in MEF 50%. No clear-cut pathological changes in ECG were found. Nevertheless, most subjects developed variations in heart rate exceeding those noted before exposure. In a few cases inversion of the T wave, and in one case atrioventricular block, were observed.