Abstract Background This study evaluates the particle dispersion involved in dental procedures carried out during orthodontic treatments. Variants such as temperature and relative humidity cabinet were considered. Methods Using a counter, pilot was conducted, which 98 consecutive recordings made appointments of patients undergoing Temperature, particles present at beginning (AR) appointment (BR...

In April 1995, the U.S. Geological Survey began a study to determine the occurrence and temporal distribution of 49 pesticides and pesticide metabolites in air and rain samples from an urban and an agricultural sampling site in Mississippi. The study was a joint effort between the National WaterQuality Assessment and the Toxics Substances Programs and was part of a larger study examining the oc...

Chloroform is a known contaminant of chlorinated drinking water and of swimming pool water disinfected with chlorine or one of its derivatives. Few data exist regarding the importance of dermal and inhalation exposure routes to the chloroform body burden resulting from domestic and recreational use of chlorinated water. In our experimental study involving 11 male swimmers, we quantified the bod...

Air sparging in conjunction with soil vapor extraction is one of many technologies currently being applied for the remediation of groundwater contaminated with volatile organic compounds (VOCs). Mass transfer at the air-water interface during air sparging is affected by various soil and VOC properties. In this study with a single air-channel apparatus, mass transfer of VOCs was shown to occur w...

The aim of this study was to establish whether the air-conditioning system in buses constitutes an additional source of indoor air contamination with fungi, and whether or not the fungi concentration depends on the period from the last disinfection of the system, combined with replacement of the cabin dust particle filter. The air samples to fungi analysis using impact method were taken in 30 b...

background: the incomplete burning of fuel in engine of vehicles, evaporation of petrol from gas stations, and also car carburetor cause unburned hydrocarbons to be emitted in ambient air of cities and gas station locations. from unburned hydrocarbons; monocyclic aromatic hydrocarbon influence to citizen's health and benzene is known as carcinogenic compounds. the objectives of this study are t...

many experimental studies have been conducted on development of the scour hole as a result of vertical jet impaction. research has shown that aeration of the nappe flow in the model is much weaker than that in the prototype. therefore, the influence of aeration on scour holes needs further study. experimental investigation of the effects of air entrainment and tail water depth on the scour hole...