Determination of an Acute No-Observed-Adverse-Effect Level (NOAEL) for Copper in Water

2001 ◽  
Vol 34 (2) ◽  
pp. 137-145 ◽  
Author(s):  
Magdalena Araya ◽  
Marie Clare McGoldrick ◽  
Leslie M. Klevay ◽  
J.J. Strain ◽  
Paula Robson ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Adverse Effect Level ◽  
Effect Level

Reevaluation of the acute toxicity of palytoxin in mice: Determination of lethal dose 50 (LD50) and No-observed-adverse-effect level (NOAEL)

Toxicon ◽  
2020 ◽  
Vol 177 ◽  
pp. 16-24 ◽  
Author(s):  
Andrea Boente-Juncal ◽  
Carmen Vale ◽  
Mercedes Camiña ◽  
J. Manuel Cifuentes ◽  
Mercedes R. Vieytes ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Acute Toxicity ◽  
Lethal Dose ◽  
Adverse Effect Level ◽  
Effect Level

scholarly journals Acute Oral Toxicity of Tetrodotoxin in Mice: Determination of Lethal Dose 50 (LD50) and No Observed Adverse Effect Level (NOAEL)

Toxins ◽  
2017 ◽  
Vol 9 (3) ◽  
pp. 75 ◽  
Author(s):  
Paula Abal ◽  
M. Louzao ◽  
Alvaro Antelo ◽  
Mercedes Alvarez ◽  
Eva Cagide ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Lethal Dose ◽  
Acute Oral Toxicity ◽  
Oral Toxicity ◽  
Adverse Effect Level ◽  
Effect Level

scholarly journals Determination of No-Observed-Adverse-Effect Level Ammonia in White Mice Through CD4 Expression

Dose-Response ◽  
2018 ◽  
Vol 16 (4) ◽  
pp. 155932581880779 ◽  
Author(s):  
Abdul Rohim Tualeka ◽  
Jihan Faradisha ◽  
Rizky Maharja
Keyword(s):  
Adverse Effect ◽  
Chemical Compounds ◽  
Control Group ◽  
Control Group Design ◽  
Post Test ◽  
Adverse Effect Level ◽  
Safe Limit ◽  
Effect Level ◽  
Acute And Chronic Effects

Background: Ammonia is one of the chemical compounds that can cause acute and chronic effects to the workers. The purpose of this study is to determine the no-observed-adverse-effect level (NOAEL) ammonia in white mice. Methods: This study applied a laboratory experimental with design post test-only control group design using white mice as an object. The process of finding the safe limit began by determining the highest dose and the lowest dose of ammonia without effect in white mice. Results: The latest research showed that the highest dose without effect is 0.0456 mg/kg and the lowest dose without effect is 0.0046 mg/kg. After determining the highest and the lowest dose of ammonia, the researcher started to determine the middle dose. The middle dose is the dose between the highest and the lowest doses with the multiplication of 1.5 starting from the lowest dose (there are 5 middle-dose variations from 5 middle concentration variations), consisting of 0.0872, 0.1309, 0.1963, 0.2944, and 0.4416 mg/m3. Conclusion: From the result of the middle dose and the lowest dose without effect, it is found the value of the highest NH3 dose without effect, which showed the highest Index Remmele Scale (IRS) CD4 before the reduction of IRS. The study concludes that the NOAEL of ammonia contained in white mice is 0.0103 mg/kg body weight of the mice.

scholarly journals Effect of chronic T-2 toxin exposure in rabbit bucks, determination of the No Observed Adverse Effect Level (NOAEL)

2013 ◽  
Vol 137 (3-4) ◽  
pp. 245-252 ◽  
Author(s):  
Melinda Kovács ◽  
Gábor Tornyos ◽  
Zsolt Matics ◽  
Miklós Mézes ◽  
Krisztián Balogh ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Toxin Exposure ◽  
Adverse Effect Level ◽  
Effect Level

Selective Vulnerability of Dopaminergic Systems To Industrial Chemicals: Risk Assessment of Related Neuroendocrine Changes

1998 ◽  
Vol 14 (1-2) ◽  
pp. 311-323 ◽  
Author(s):  
Antonio Mutti ◽  
Audrey Smargiassi
Keyword(s):  
Adverse Effect ◽  
Selective Vulnerability ◽  
Common Finding ◽  
Serum Prolactin ◽  
Industrial Chemicals ◽  
Limit Values ◽  
Reference Limit ◽  
Individual Level ◽  
Adverse Effect Level ◽  
Effect Level

Increased serum prolactin (PRL) is a common finding among subjects exposed to styrene, perchloroethylene, lead (Pb), and manganese (Mn) at levels below the current threshold limit values. On a group basis, abnormally high basal PRL shows a dose-related distribution among workers exposed to styrene, Pb, and Mn. On the basis of dose-response relationships, the benchmark doses (BMD) for styrene metabolites in urine, lead in blood (Pb-B), and Mn in urine (Mn-U), are 4 mg/g creatinine, 112 μg/L, and 0.3 μg/L, respectively. Noteworthy, the BMD for Mn-U and Pb-B is well below the upper reference limit. A shift in the distribution but not in the prevalence of abnormally high values of serum PRL was observed among perchloroethylene-exposed dry cleaners, which makes interpretation in terms of risk difficult. The measurement of PRL thus provides opportunities for early identification of excess exposure to neurotoxic chemicals affecting dopaminergic control of pituitary secretion. For styrene, Pb, and Mn the BMD provides an objective and statistically determined threshold, which seems to be in good agreement with the estimated no-observed-adverse-effect-level (NOAEL). The NOAEL, however, is based on traditional approaches that require the application of uncertainty factors, e.g., a default factor of 10 when extrapolating the NOAEL from the lowest-observed- adverse-effect-level (LOAEL). Due to its sensitivity to a number of potential confounders, caution must be exercised when using PRL as a screening test at the individual level. Also, age and sex dependent variations in susceptibility may hamper extrapolations from the occupational settings to the general population.

scholarly journals Lowest observed adverse effect level of pulmonary pathological alterations due to nitrous acid exposure in guinea pigs

2020 ◽  
Vol 25 (1) ◽  
Author(s):  
Masayuki Ohyama ◽  
Hiroshi Nishimura ◽  
Kenichi Azuma ◽  
Chika Minejima ◽  
Norimichi Takenaka ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Smooth Muscle ◽  
Electron Microscope ◽  
Epithelial Cells ◽  
Guinea Pigs ◽  
Pulmonary Emphysema ◽  
Nitrous Acid ◽  
Bronchial Epithelial ◽  
Adverse Effect Level ◽  
Effect Level

Abstract Background We previously demonstrated that continuous exposure to nitrous acid gas (HONO) for 4 weeks, at a concentration of 3.6 parts per million (ppm), induced pulmonary emphysema-like alterations in guinea pigs. In addition, we found that HONO affected asthma symptoms, based on the measurement of respiratory function in rats exposed to 5.8 ppm HONO. This study aimed to investigate the dose-response effects of HONO exposure on the histopathological alterations in the respiratory tract of guinea pigs to determine the lowest observed adverse effect level (LOAEL) of HONO. Methods We continuously exposed male Hartley guinea pigs (n = 5) to four different concentrations of HONO (0.0, 0.1, 0.4, and 1.7 ppm) for 4 weeks (24 h/day). We performed histopathological analysis by observing lung tissue samples. We examined samples from three guinea pigs in each group under a light microscope and measured the alveolar mean linear intercept (Lm) and the thickness of the bronchial smooth muscle layer. We further examined samples from two guinea pigs in each group under a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Results We observed the following dose-dependent changes: pulmonary emphysema-like alterations in the centriacinar regions of alveolar ducts, significant increase in Lm in the 1.7 ppm HONO-exposure group, tendency for hyperplasia and pseudostratification of bronchial epithelial cells, and extension of the bronchial epithelial cells and smooth muscle cells in the alveolar duct regions. Conclusions These histopathological findings suggest that the LOAEL of HONO is < 0.1 ppm.

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