The levels of fluoride airborne particulates emitted from welding processes were investigated. They were sampled with the patented IOM Sampler, developed by J. H. Vincent and D. Mark at the Institute of Occupational Medicine (IOM), personal inhalable sampler for simultaneous collection of the inhalable and respirable size fractions. Ion chromatography with conductometric detection was used for quantitative analysis. The efficiency of fluoride extraction from the cellulose filter of the IOM sampler was examined using the standard sample of urban air particle matter SRM-1648a. The best results for extraction were obtained when water and the anionic surfactant N-Cetyl-N–N–N-trimethylammonium bromide (CTAB) were used in an ultrasonic bath. The limits of detection and quantification for the whole procedure were 8 ?g/L and 24 ?g/L, respectively. The linear range of calibration was 0.01–10 mg/L, which corresponds to 0.0001–0.1 mg of fluorides per m3 in collection of a 20 L air sample. The concentration of fluorides in the respirable fraction of collected air samples was in the range of 0.20–1.82 mg/m3, while the inhalable fraction contained 0.23–1.96 mg/m3 of fluorides during an eight-hour working day in the welding room.
[Biological exposure limits caused by co exposure to fluoride and arsenic based on Wnt signaling pathway].
Chronic fluoride-arsenic combined poisoning is a global public health problem. While the cause of the disease is clear, the pathogenesis is unknown. Given that there is no specific treatment, early prevention is particularly important. Biological exposure limits are designed to investigate the maximum allowable concentration of harmful effects from exogenous
A quantitative look at fluorosis, fluoride exposure, and intake in children using a health risk assessment approach
The prevalence of dental fluorosis in the United States has increased during the last 30 years. In this study, we used a mathematical model commonly employed by the U.S. Environmental Protection Agency to estimate average daily intake offluoride via all applicable exposure pathways contributing to fluorosis risk for infants and children
Fluoride intake and prevalence of dental fluorosis: trends in fluoride intake with special attention to infants
BACKGROUND: Although the predominant beneficial effect of fluoride occurs locally in the mouth, the adverse effect, dental fluorosis, occurs by the systemic route. The caries attack rate in industrialized countries, including the United States and Canada, has decreased dramatically over the past 40 years. However, the prevalence of dental fluorosis
The case for eliminating the use of dietary fluoride supplements for young children.
Fluoride supplements have been used for years to prevent dental caries; nevertheless, there are three reasons why their use is inappropriate today among infants and young children in the United States. Evidence for the efficacy of fluoride supplements when used from birth or soon after is weak, supplements are a
A study of fluoride contents in foods (in Japan).
It is important to understand the fluoride ingestion in daily life when a community is planning to commence the caries prevention program using fluoride. In this study, samples were collected from 14 groups of the 65 food items availadle at a super-market in Fukuoka. The foods were measured 8 times ot
Related Studies :