Nanotechnologies. Characterization of nanoparticles in inhalation exposure chambers for inhalation toxicity testing

2011 ◽  
Keyword(s):  
Inhalation Exposure ◽  
Toxicity Testing ◽  
Inhalation Toxicity

scholarly journals Ethylene Oxide: Acute Four-Hour and One-Hour Inhalation Toxicity Testing in Rats

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
William M. Snellings ◽  
Donald J. Nachreiner ◽  
Lynn H. Pottenger
Keyword(s):  
Ethylene Oxide ◽  
Inhalation Exposure ◽  
Clinical Signs ◽  
Toxicity Testing ◽  
Inhalation Toxicity ◽  
Confidence Limits ◽  
Pulmonary Congestion ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Irregular Breathing

Ethylene oxide was tested on groups of rats for either 4-hour or 1-hour inhalation exposure, followed by 14 days of observation. Groups of five Sprague-Dawley rats/sex were exposed, and clinical signs and mortality were recorded. Clinical signs noted included irregular breathing, absence of certain reflexes, and tremors. Rats that died had moderate to severe pulmonary congestion. The calculated LC50values, reported as ppm by volume (with 95% confidence limits), were as follows. 4-hour LC50values were 1972 (1887 to 2061) ppm for males; 1537 (1391 to 1698) ppm for females; 1741 (1655 to 1831) ppm for the combined sexes. The 1-hour LC50values were 5748 (5276 to 6262) ppm for males; 4439 (4034 to 4884) ppm for females; 5029 (4634 to 5459) ppm for the combined sexes.

Hormesis - Implications for risk assessment caloric intake (body weight) as an exemplar

1998 ◽  
Vol 17 (8) ◽  
pp. 454-459 ◽  
Author(s):  
Angelo Turturro ◽  
Bruce Hass ◽  
Ronald W Hart
Keyword(s):  
Risk Assessment ◽  
Caloric Intake ◽  
Toxicity Testing ◽  
Risk Assessments ◽  
Specific Information ◽  
Response Curves ◽  
Hormetic Effect ◽  
The Impact ◽  
Hormetic Response

Hormesis can be considered as a parameter which has a non-monotonic relationship with some endpoint. Since caloric intake is such a parameter, and the impact of this parameter on risk assessment has been fairly well characterized, it can provide clues as to how to integrate the information from a hormetic parameter into risk assessments for toxicants. Based on the work with caloric intake, one could: (a) define a biomarker for hormetic effect; (b) integrate specific information on when in the animals lifespan the parameter is active to influence parameters such as survival; (c) evaluate component effects of the overall hormetic response; and (d) address the consequences of a non-monotonic relationship between the hormetic parameter and endpoints critical for risk assessment. These impacts on risk assessments have been characterized for chronic tests, but are also true for short-term tests. A priority is the characterization of the dose-response curves for hormetic parameters. This quantification will be critical in utilizing them in risk assessment. With this information, one could better quantitatively address the changes one expects to result from the hormetic parameter, and limit the uncertainty and variability which occurs in toxicity testing.

scholarly journals Effect of electric heating and ice added to the bowl on mainstream waterpipe semivolatile furan and other toxicant yields

2019 ◽  
Vol 29 (Suppl 2) ◽  
pp. s110-s116 ◽  
Author(s):  
Marielle C Brinkman ◽  
Andreas A Teferra ◽  
Noura O Kassem ◽  
Nada OF Kassem
Keyword(s):  
Inhalation Exposure ◽  
Electric Heating ◽  
Inhalation Toxicity ◽  
Toxicity Data ◽  
Total Particulate Matter ◽  
Mutagenic Potential ◽  
Waterpipe Tobacco Smoking ◽  
Educational Campaigns ◽  
Ice Water ◽  
Smoking Behaviours

ObjectivesWe examined mainstream total particulate matter, nicotine, cotinine, menthol, pyrene, carbon monoxide (CO) and semivolatile furan yields from a commercial waterpipe with two methods for heating the tobacco, quick-light charcoal (charcoal) and electric head (electric) and two water bowl preparations: with (ice) and without ice (water).MethodsEmissions from a single brand of popular waterpipe tobacco (10 g) were generated using machine smoking according to a two-stage puffing regimen developed from human puffing topography. Tobacco and charcoal consumption were calculated for each machine smoking session as mass lost, expressed as a fraction of presmoking mass.ResultsThe heating method had the greatest effect on toxicant yields. Electric heating resulted in increases in the fraction of tobacco consumed (2.4 times more, p<0.0001), mainstream nicotine (1.4 times higher, p=0.002) and semivolatile furan yields (1.4 times higher, p<0.03), and a decrease in mainstream CO and pyrene yields (8.2 and 2.1 times lower, respectively, p<0.001) as compared with charcoal. Adding ice to the bowl resulted in higher furan yields for electric heating. Menthol yields were not different across the four conditions and averaged 0.16±0.03 mg/session. 2-Furaldehyde and 5-(hydroxymethyl)−2-furaldehyde yields were up to 230 and 3900 times higher, respectively, than those reported for cigarettes.ConclusionWaterpipe components used to heat the tobacco and water bowl preparation can significantly affect mainstream toxicant yields. Mainstream waterpipe tobacco smoke is a significant source of inhalation exposure to semivolatile furans with human carcinogenic and mutagenic potential. These data highlight the need for acute and chronic inhalation toxicity data for semivolatile furans and provide support for the establishment of limits governing sugar additives in waterpipe tobacco and educational campaigns linking waterpipe tobacco smoking behaviours with their associated harm.

Development and characterization of a resistance spot welding aerosol generator and inhalation exposure system

2014 ◽  
Vol 26 (12) ◽  
pp. 708-719 ◽  
Author(s):  
Aliakbar Afshari ◽  
Patti C. Zeidler-Erdely ◽  
Walter McKinney ◽  
Bean T. Chen ◽  
Mark Jackson ◽  
...  
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Inhalation Exposure ◽  
Exposure System ◽  
Resistance Spot ◽  
Aerosol Generator
Sign in / Sign up

Export Citation Format

Share Document