Assessment of the fit and wearability of commercially available KN95 respirators for children in Indonesia and Nepal

The purpose of this study was to determine how well KN95 respirators, marketed for children, fit the faces of children aged 6–13 years old in two urban sites with elevated levels of air pollution: Kathmandu, Nepal and Bandung, Indonesia. The wearability of the tested respirators and the children's style preferences were also assessed.Sixty children, 30 in each country, were recruited and were fit tested with three different ear loop respirators in two combinations (with and without an additional adjustable ear loop clip worn around the head). The fit factor for each respirator was determined using a modified fit test protocol for filtering face piece respirators using a TSI PortaCount™ Respirator Fit Tester 8048. Facial dimensions were measured using callipers. The wearability of the respirators and children's style preferences were assessed through questionnaires administered after the fit tests.Most fit factors were less than 10, i.e. less than 90 % reduction in exposure. In both countries, using an additional ear loop clip was associated with increases in fit factor of 42 and 50 % for Indonesian and Nepalese respirators, respectively. There were no significant differences among the respirators for any of the perceptions: comfort, feeling hot, breathability, fit, embarrassment or appearance for either country. The appearance of the respirator was important to the children. Although the use of an additional ear loop clip improved the fit, the respirators were generally too large for the children's faces to achieve a good fit. Respirators marketed for children should be better designed to suit their facial dimensions

Occupational dermal exposure to nanoparticles and nano-enabled products:Part I − Factors affecting skin absorption

The paper reviews and critically assesses the evidence on the relevance of various skin uptake pathways for engineered nanoparticles, nano-objects, their agglomerates and aggregates (NOAA). It focuses especially in occupational settings, in the context of nanotoxicology, risk assessment, occupational medicine, medical/epidemiological surveillance efforts, and the development of relevant exposure assessment strategies. Skin uptake of nanoparticles is presented in the context of local and systemic health effects, especially contact dermatitis, skin barrier integrity, physico-chemical properties of NOAA, and predisposing risk factors, such as stratum corneum disruption due to occupational co-exposure to chemicals, and the presence of occupational skin diseases. Attention should be given to: (1) Metal NOAA, since the potential release of ions may induce local skin effects (e.g. irritation and contact dermatitis) and absorption of toxic or sensitizing metals; (2) NOAA with metal catalytic residue, since potential release of ions may also induce local skin effects and absorption of toxic metals; (3) rigid NOAA smaller than 45nm that can penetrate and permeate the skin; (4) non rigid or flexible NOAA, where due to their flexibility liposomes and micelles can penetrate and permeate the intact skin; (5) impaired skin condition of exposed workers. Furthermore, we outline possible situations where health surveillance could be appropriate where there is NOAA occupational skin exposures, e.g. when working with nanoparticles made of sensitizer metals, NOAA containing sensitizer impurities, and/or in occupations with a high prevalence of disrupted skin barrier integrity. The paper furthermore recommends a stepwise approach to evaluate risk related to NOAA to be applied in occupational exposure and risk assessment, and discusses implications related to health surveillance, labelling, and risk communication

Trends in wood dust inhalation exposure in the UK, 1985-2005

OBJECTIVES: Wood dust data held in the Health and Safety Executive (HSE) National Exposure DataBase (NEDB) were reviewed to investigate the long-term changes in inhalation exposure from 1985 to 2005. In addition, follow-up sampling measurements were obtained from selected companies where exposure measurements had been collected prior to 1994, thereby providing a follow-up period of at least 10 years, to determine whether changes in exposure levels had occurred, with key staff being interviewed to identify factors that might be responsible for any changes observed. METHODS: Analysis of the temporal trend in exposure concentrations was performed using Linear Mixed Effect Models on the log-transformed NEDB data set and expressed as the relative annual change in concentration. RESULTS: For the NEDB wood dust data, an annual decline of geometric mean (GM) exposure of 8.1% per year was found based on 1459 exposure measurements collected between 1985 and 2003. This trend was predominantly observed in data from inspection visits (measurements collected on a mandatory basis by a Specialist HSE Inspector) (n = 1009), while data from representative surveys (measurements collected on a voluntary basis to provide information on current practices and exposures) remained relatively stable. Ten follow-up surveys in individual workplaces in 2004-2005 resulted in 70 new measurements and for each of the companies resurveyed, the GM of the wood dust exposure decreased between sampling surveys. CONCLUSION: Analysis of the temporal trend in UK wood dust exposure concentrations revealed declines of 8% per annum. Interviews with key long-serving employees and management suggest that factors such as technological changes in production processes, response to new legislation, and enforcement agency inspections, together with global economic trends, could be linked to the downward trends observed