Neurobehavioral Effects of Acute Exposure to Isoparaffinic and Cycloparaffinic Hydrocarbons

2011 ◽  
Vol 30 (6) ◽  
pp. 715-734 ◽  
Author(s):  
Richard H. McKee ◽  
J. H. C. M. Lammers ◽  
H. Muijser ◽  
David E. Owen
Keyword(s):  
Central Nervous System ◽  
Visual Discrimination ◽  
Discrimination Performance ◽  
Clinical Effects ◽  
Occupational Exposure Limits ◽  
Exposure Limits ◽  
Discrimination Testing ◽  
Effect Level ◽  
Neurobehavioral Effects ◽  
Cns Effects

This article reports neurobehavioral tests in rats with C5-C11 isoparaffinic and cycloparaffinic hydrocarbons. Testing, conducted shortly after exposure, evaluated the effects in several domains including clinical effects, motor activity, functional observations, and visual discrimination performance. Isopentane and cyclopentane did not produce any evidence of acute central nervous system (CNS) effects at levels up to 20 000 mg/m3. A C6/C7 mixed cycloparaffinic solvent produced minor, reversible changes in latency to response in visual discrimination testing at 14 000 mg/m3; the no-effect level was 4200 mg/m3. A C8 isoparaffin produced no effects at 14 000 mg/m3, the highest level tested. A C9/C11 isoparaffinic solvent produced minor acute CNS effects at 5000 mg/m3, with 1500 mg/m3 as the no-effect level. A C10 cycloparaffinic solvent did not produce any statistically significant CNS effects at 5000 mg/m3. These studies were designed to provide data that may be useful in setting occupational exposure limits for C5-C11 isoparaffinic and cycloparaffinic hydrocarbons.

Neurobehavioral Effects of Acute Exposure to Normal (n-) Paraffins

2011 ◽  
Vol 30 (1) ◽  
pp. 47-58 ◽  
Author(s):  
J. H. C. M. Lammers ◽  
H. Muijser ◽  
D. E. Owen ◽  
B.M. Kulig ◽  
R. H. McKee
Keyword(s):  
Molecular Weight ◽  
Central Nervous System ◽  
Visual Discrimination ◽  
Discrimination Performance ◽  
Clinical Effects ◽  
Compelling Evidence ◽  
Effect Level ◽  
Neurobehavioral Effects ◽  
Cns Effects ◽  
Metabolic Induction

This article reports the results of neurobehavioral tests on C5-C10 normal paraffinic constituents (n-paraffins). Shortly after exposure, effects were evaluated in several domains including clinical effects, motor activity, functional observations, and visual discrimination performance. The representative C5 n-paraffin, n-pentane, did not produce any evidence of acute central nervous system (CNS) effects at levels up to 20 000 mg/m3. Similarly, there was no compelling evidence that n-octane (C8) produced CNS effects at 14 000 mg/m3, the highest concentration tested. n-decane (C10) produced minor, reversible acute CNS effects at 5000 mg/m3, with 1500 mg/m3 as the no-effect level. Consistent with literature data, there seemed to be a relationship between increasing molecular weight up to C10 and acute CNS effects. However, the CNS effects were reversible. Repeated exposures did not provide evidence of metabolic induction.

Neurobehavioral Effects of Acute Exposure to Aromatic Hydrocarbons

2010 ◽  
Vol 29 (3) ◽  
pp. 277-290 ◽  
Author(s):  
Richard H. McKee ◽  
J. H. C. M. Lammers ◽  
H. Muijser ◽  
D. E. Owen ◽  
B. M. Kulig
Keyword(s):  
Visual Discrimination ◽  
Discrimination Performance ◽  
Clinical Effects ◽  
High Exposure ◽  
Molecular Weights ◽  
Trimethyl Benzene ◽  
The Central Nervous System ◽  
Exposure Levels ◽  
Alkyl Benzenes ◽  
Neurobehavioral Effects

This article reports the results of neurobehavioral tests on representative aromatic constituents, specifically C9 to C11 species. The testing evaluated effects in several domains including clinical effects, motor activity, functional observations, and visual discrimination performance. Exposures ranging from 600 to 5000 mg/m3, depending on the molecular weights of the specific aromatic constituents, produced minor, reversible effects on the central nervous system (CNS), particularly in the domains of gait and visual discrimination. There was little evidence of effects at lower exposure levels. There was some evidence of respiratory effects at 5000 mg/m3 in 1 study, and there were also minor changes in body weight and temperature. The CNS effects became less pronounced with repeated exposures, corresponding to lower concentrations in the brain of 1 representative substance, 1,2,4-trimethyl benzene (TMB). At high exposure levels, the alkyl benzenes apparently induced their own metabolism, increasing elimination rates.

scholarly journals Industry Derived Occupational Exposure Limits: A Survey of Professionals on the Dutch System of Exposure Guidelines

2019 ◽  
Vol 63 (9) ◽  
pp. 1004-1012
Author(s):  
Linda Schenk ◽  
Maaike J Visser ◽  
Nicole G M Palmen
Keyword(s):  
Occupational Exposure ◽  
Inhalation Exposure ◽  
Professional Organization ◽  
Occupational Exposure Limits ◽  
Exposure Limits ◽  
Public And Private ◽  
Web Based ◽  
Effect Level ◽  
The Government ◽  
Nederlandse Vereniging Voor

Abstract The Netherlands’ system for occupational exposure limits (OELs) encompasses two kinds of OELs: public and private. Public OELs are set by the government. Private OELs are derived by industry and cover all substances without a public OEL. In parallel, the regulation concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) has introduced an exposure guidance value similar to the OEL, namely the Derived No-Effect Level (DNEL) for workers’ inhalation exposure. This study aimed to investigate issues encountered by occupational health professionals regarding private OELs, and how they perceive the DNELs for workers in relation to private OELs. Towards this aim, we sent out a web-based questionnaire to the members of the Dutch professional organization for occupational hygienists (Nederlandse Vereniging voor Arbeidshygiëne [NVVA], n = 513) and to members of the Dutch professional organization for safety engineers (NVVK, n = 2916). Response rates were 27% (n = 139) and 7% (n = 198), respectively. More occupational hygienists (59%) than safety engineers (17%) reported to derive private OELs themselves. Our respondents reported several challenges with the derivation of private OELs. Fifty-one percent of the occupational hygienists and 20% of the safety engineers stated to see a role of REACH Registrants’ worker DNELs as private OELs. However, more than half of our respondents were undecided or unfamiliar with worker DNELs. In addition, stated opinions on where worker DNELs fit in the hierarchy of private OELs varied considerably. To conclude, both these professional groups derive private OELs and stated that they need more guidance for this. Furthermore, there is a lack of clarity whether worker DNELs may qualify as private OELs, and where they would fit in the hierarchy of private OELs.

Neurobehavioral Effects of Cyclohexane in Rat and Human

2009 ◽  
Vol 28 (6) ◽  
pp. 488-497 ◽  
Author(s):  
J. H. C. M. Lammers ◽  
H. H. Emmen ◽  
H. Muijser ◽  
E. M. G. Hoogendijk ◽  
R. H. McKee ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Discrimination Performance ◽  
Internal Exposure ◽  
Psychomotor Speed ◽  
Significant Treatment ◽  
High Exposure ◽  
Observational Measures ◽  
Human Volunteers ◽  
Neurobehavioral Effects

The neurobehavioral effects of inhaled cyclohexane in rats and humans are investigated to define relationships between internal doses and acute central nervous system effects. Rats are exposed for 3 consecutive days at target concentrations of 0, 1.4, 8, and 28 g/m3, 8 h/d. Measurements include standardized observational measures, spontaneous motor activity assessments, and learned visual discrimination performance. Cyclohexane concentrations in blood and brain are measured to assess internal exposure. Human volunteers are exposed for 4 hours to 86 or 860 mg/m3 in 2 test sessions. Neurobehavioral effects are measured using a computerized neurobehavioral test battery. In rats, there are slight reductions in psychomotor speed in the high-exposure group but minimal central nervous system effects. In humans, there are no significant treatment-related effects at the levels tested.

Ototoxicity of trichloroethylene in concentrations relevant for the working environment

2008 ◽  
Vol 27 (3) ◽  
pp. 195-200 ◽  
Author(s):  
A Vyskocil ◽  
T Leroux ◽  
G Truchon ◽  
F Lemay ◽  
F Gagnon ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Convincing Evidence ◽  
Working Environment ◽  
Exposure Limits ◽  
Additive Interaction ◽  
Animal Data ◽  
Short Term Exposure ◽  
Adverse Effect Level ◽  
Effect Level ◽  
Permissible Exposure Limits

Organic solvents can cause hearing loss themselves or promote noise-induced hearing loss. The objective of this study was to review the literature on the effects of low-level exposure to trichloroethylene on the auditory system and consider its relevance for the occupational settings. Both human and animal investigations were evaluated only for realistic exposure concentrations based on the Quebec permissible exposure limits: 50 ppm 8-h time-weighed average exposure value (TWAEV) and 200 ppm short-term exposure value (STEV). In humans, the upper limit for considering ototoxicity data relevant to the occupational exposure situation was set at the STEV. Animal data were evaluated only for exposure concentrations up to 100 times the TWAEV. There is no convincing evidence of trichloroethylene-induced hearing losses in workers. In rats, trichloroethylene affects the auditory function mainly in the cochlear mid- to high-frequency range with a lowest observed adverse effect level (LOAEL) of 2000 ppm. No studies on ototoxic interaction after combined exposure to noise and trichloroethylene were identified in humans. In rats, supra-additive interaction was reported. Further studies with sufficient data on the trichloroethylene exposure of workers are necessary to make a definitive conclusion. In the interim, we recommend considering trichloroethylene as an ototoxic agent.

scholarly journals Possible hazards of work environment in metal processing industry in Latvia

2010 ◽  
Vol 64 (1-2) ◽  
pp. 61-65
Author(s):  
Inese Mārtiņsone ◽  
Mārīte-Ārija Baķe ◽  
Žanna Martinsone ◽  
Maija Eglīte
Keyword(s):  
Risk Factors ◽  
Occupational Exposure ◽  
Work Environment ◽  
Occupational Safety ◽  
Poor Quality ◽  
Occupational Exposure Limits ◽  
Exposure Limits ◽  
Processing Industry ◽  
Metal Processing ◽  
Metal Processing Industry

Possible hazards of work environment in metal processing industry in Latvia The aim of this study was to investigate risk factors in the work environment of Latvian metal processing industry using the database of the Laboratory of Hygiene and Occupational Diseases of the Institute of Occupational Safety and Environmental Health, Rīga Stradiņš University. During the period between 1996 and 2005, 703 measurements were made in metalworking enterprises. In Latvia, approximately 2.4% of the workforce is involved in the metal processing industry. Physical (noise, lighting, vibration) and chemical (abrasive dust, welding aerosol and contained metals) risk factors were analysed. In the assessed metalworking workplaces, the work environment was estimated to be of poor quality, because occupational exposure limits or recommended values were exceeded in 42% (n = 294) of cases. Noise, manganese and welding aerosols most often exceeded the occupational exposure limits or recommended values, the significance was P < 0.001, P < 0.01 and P < 0.05, respectively.

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