Documents humidity 8 results

"Sensory effects in eyes and airways are common symptoms reported by aircraft crew and office workers. Neurological symptoms, such as headache, have also been reported. To assess the commonality and differences in exposures and health symptoms, a literature search of aircraft cabin and office air concentrations of non-reactive volatile organic compounds (VOCs) and ozone-initiated terpene reaction products were compiled and assessed. Data for tricresyl phosphates, in particular tri-ortho-cresyl phosphate (ToCP), were also compiled, as well as information on other risk factors such as low relative humidity.

A conservative health risk assessment for eye, airway and neurological effects was undertaken based on a “worst-case scenario” which assumed a simultaneous constant exposure for 8 h to identified maximum concentrations in aircraft and offices. This used guidelines and reference values for sensory irritation for eyes and upper airways and airflow limitation; a tolerable daily intake value was used for ToCP. The assessment involved the use of hazard quotients or indexes, defined as the summed ratio(s) (%) of compound concentration(s) divided by their guideline value(s).



The concentration data suggest that, under the assumption of a conservative “worst-case scenario”, aircraft air and office concentrations of the compounds in question are not likely to be associated with sensory symptoms in eyes and airways. This is supported by the fact that maximum concentrations are, in general, associated with infrequent incidents and brief exposures. Sensory symptoms, in particular in eyes, appear to be exacerbated by environmental and occupational conditions that differ in aircraft and offices, e.g., ozone incidents, low relative humidity, low cabin pressure, and visual display unit work. The data do not support airflow limitation effects. For ToCP, in view of the conservative approach adopted here and the rareness of reported incidents, the health risk of exposure to this compound in aircraft is considered negligible."

"Subjective and physiological responses were obtained from 6 subjects wearing a ventilated face mask while exercising for 15min on a bicycle ergometer. Different combinations of ambient air temperatures (7o, 16o, 25oC) and mask air temperatures (22o, 27o, 33oC) were studied together with two different air humidities inside the mask (61% and 86% RH). Control experiments were performed without the mask. Skin temperatures, heart rates and skin wettedness were monitored during exercise. The subjects' acceptance of the mask and of the thermal environment, thermal sensation, sensations of discomfort, sweating and skin wettedness, and their judgment of the effort involved in breathing were assessed at the end of the 15min exercise period. At ambient temperatures of 7oC and 25oC, the acceptance of the thermal work conditions decreased. In a warm environment a mask air temperature <=27oC was 100% acceptable and increased the acceptance of the thermal environment. In a cool environment, a mask air temperature >=27oC was 100% acceptable. Warm humid air significantly decreased acceptance of the mask conditions."

"This code provides guidance on the role and obligations of competent authorities and the responsibilities, duties and rights of employers, workers and all other parties involved, with regard to hazardous ambient factors, in particular in (a) setting up legal, administrative and effective frameworks for the prevention and reduction of hazards and risks; (b) the aims of and mechanisms for eliminating, minimizing and controlling hazards; (c) the assessment of risk and of the measurs that need to be taken; (d) the surveillance of the working environment; and (e) providing information and training to workers."

"Working and living inside buildings expose people to all kinds of biological contaminants. This is a report on health hazards posed by the presence in indoor air of biological contaminants including suspended viable particles, suspended allergens, animal dander, fragments of dust mites and other biologically derived suspended material. Emphasis is placed on construction materials and building elements such as cooling towers, humidifiers, ventilation systems and design features leading to high indoor humidity, that can introduce or spread airborne biological contaminants. The first chapter catalogues some 16 infectious diseases, allergic reactions and other health risks linked to the presence of biological contaminants in indoor air. The second chapter presents hazard assessment and offers advice on strategies available for the investigation of individuals or populations suffering from suspected indoor air-related infectious diseases including Legionnaires disease, allergic reactions or toxic reactions following the inhalation of mycotoxins. Other chapters review methods for environmental sampling and analysis, discuss the main sources of microbiological contaminants in buildings and identify factors in the indoor environment that can enhance the risk of contamination. The final chapter discusses strategies for control, concluding that most biological aerosols in buildings are caused by persistent moisture and inadequate ventilation, and that proper building design and maintenance are needed to reduce acute infections and allergic episodes caused by contaminated indoor air."

"Humid heat impacts a large portion of the world's population that works outdoors. Previous studies have quantified humid heat impacts on labor productivity by relying on exposure response functions that are based on uncontrolled experiments under a limited range of heat and humidity. Here we use the latest empirical model, based on a wider range of temperatures and humidity, for studying the impact of humid heat and recent climate change on labor productivity. We show that globally, humid heat may currently be associated with over 650 billion hours of annual lost labor (148 million full time equivalent jobs lost), 400 billion hours more than previous estimates. These differences in labor loss estimates are comparable to losses caused by the COVID-19 pandemic. Globally, annual heat-induced labor productivity losses are estimated at 2.1 trillion in 2017 PPP$, and in several countries are equivalent to more than 10% of gross domestic product. Over the last four decades, global heat-related labor losses increased by at least 9% (>60 billion hours annually using the new empirical model) highlighting that relatively small changes in climate (<0.5 °C) can have large impacts on global labor and the economy."