proposing a noise standards should be considered seriously by the governmental authorities because of the prevalence of hazardous noise exposure and the seriousness of the effects . in a survey founded by world health organization’s regional office in iran, the existing as well as gathered data from field were applied to propose a national occupational noise exposure limit. the collected data p...

The correlations of lethal doses of various industrial chemicals for rats and mice with occupational exposure limit values were investigated. 50% lethal dose (LD50) values obtained by oral (p.o.) and intraperitoneal (i.p.) injection and 50% lethal concentration (LC50) values obtained by inhalation exposure were collected from Registry of Toxic Effects of Chemical Substances (RTECS). Threshold L...

introduction blue light is a part of the spectrum with the highest energy content, which can reach the retina. the damage that it can cause to the retina is called photochemical or blue-light retinal injury. for the retinal injury assessment of the photochemical and aphakic retinal hazards in the wavelength range of 300-700 nm, use of effective spectral radiance limits (w.m-2.sr-1) seems to be ...

The history of sheep scab is briefly discussed since it was first mentioned in 180 BC. It was probably introduced to South Africa by the early settlers and was mentioned as a problem by Simon van der Stel, although its cause was only discovered in 1809. Various measures taken over the centuries to control or eradicate the disease, which has always been of considerable economic importance, are d...

Several cases of exposure to hand-transmitted shocks in two different factories were studied with an intention to improve our knowledge about the influence of the impulsive components of vibration on human being. Two types of shocks affecting the workers could be distinguished, i.e., shocks having small amount of energy at frequencies higher than 100 Hz and shocks having relatively high frequen...

conclusions the adoption of 85 dba as the permissible exposure limit has preserved hearing threshold level among participants at 3000 hz compared to those who embraced 90 dba. patients and methods this is an intervention study done on two automobile factories. there were 203 employees exposed to noise levels beyond the action level. hearing protection devices were distributed to reduce noise le...