Relevance of carcinogenicity bioassays in mice in assessing potential health risks associated with exposure to methylene chloride

1998 ◽  
Vol 17 (2) ◽  
pp. 84-87 ◽  
Author(s):  
Robert G Liteplo ◽  
G W Long ◽  
M E Meek
Keyword(s):  
Risk Assessment ◽  
Subcellular Localization ◽  
Human Health ◽  
Quantitative Methods ◽  
Methylene Chloride ◽  
Human Health Risk ◽  
Glutathione S Transferase ◽  
Potential Health ◽  
Intact Cells

Considerable research has been conducted to identify possible mechanisms of the carcinogenicity of methylene chloride in rodents, and to ascertain whether the observed increased incidences of liver and lung tumours in mice exposed to this substance, are relevant in assessing the potential hazards and risks to human health. On the basis of a study that purported to show qualitative differences between murine and human tissues, in the subcellular localization of the Theta-class glutathione S-transferase enzyme responsible for converting methylene chloride to a putative highly unstable, but reactive genotoxic metabolite, it was suggested that the mouse is an inappropriate model for human health risk assessment. However, other studies conducted in vitro with intact cells do not support the hypothesis that a putatively reactive metabolite of methylene chloride must be generated only within the nucleus in order to be able to interact with genomic DNA. Moreover, investigations employing semi-quantitative methods of mRNA hybridization are not convincing in identifying the subcellular localization of active Theta class glutathione S-transferase, and do not support the hypothesis of the differential subcellular localization of this enzyme within the nucleus of mouse, but not human cells. There is therefore, insufficient evidence to support the view that qualitative differences between humans and mice in the subcellular distribution of Theta-class glutathione S-transferase, renders carcinogenicity studies conducted with mice irrelevant in human hazard identi-fication and risk assessment.

Risk Assessment of Some Heavy Metals in Two Fish Species Oreochromis Niloticus and Clarias Gariepinus from Sharqia Province, Egypt

2021 ◽  
Vol 8 (1) ◽  
pp. 1-5
Author(s):  
Nahla S El-Shenawy ◽  
Heba N Gad EL-Hak ◽  
Mahi A Ghobashy ◽  
Maha FM Soliman ◽  
Farida A Mansour ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Human Health ◽  
Health Risks ◽  
Oreochromis Niloticus ◽  
Clarias Gariepinus ◽  
Human Health Risk ◽  
Dry Weight ◽  
Critical Problem ◽  
Potential Health

Accumulation of heavy metals in fish is considered a critical problem for human health. Therefore, the study aimed to quantify the concentrations of iron (Fe), zinc (Zn), manganese (Mn), and lead (Pb) in Oreochromis niloticus and Clarias gariepinus from two areas in Al Sharqia governorate, Egypt, from September 2017 to August 2018. A human health risk assessment was conducted to evaluate the potential hazards associated with fish consumption. Metals concentrations (mg/kg dry weight) in muscles of catfish ranged 1.88-221.26 for Fe; 1.78-19.77 for Zn; BDL-238.51 for Mn; BDL-22.75 for Pb. In muscles of tilapia fish metals concentrations ranged 7.96-149.10 for Fe; 1.20-19.77 for Zn; BDL-230.82 for Mn; BDL-25.93 for Pb. Pb had Hazard quotients (HQs) which indicated potential health risks to tilapia consumers at both study areas and catfish consumers at the Faqous area. Fishermen were at higher risk compared to the other consumers.

Health risk assessment of nitrate pollution in shallow groundwater: a case study in Changchun New District, China

2019 ◽  
pp. 45-58 ◽  
Author(s):  
Hui Tian ◽  
Xiujuan Liang ◽  
Yan Gong ◽  
Zhuang Kang ◽  
Hongtao Jin
Keyword(s):  
Risk Assessment ◽  
Health Risk ◽  
Human Health ◽  
Health Risk Assessment ◽  
Health Risks ◽  
Human Health Risk ◽  
Nitrate Pollution ◽  
Assessment Model ◽  
Potential Health ◽  
Skin Contact

High concentrations of nitrate in groundwater pose a threat to human health. To quantify groundwater nitrate pollution in China's Changchun New District and evaluate its human health risks, 98 groundwater samples were collected and analyzed. The spatial distribution of groundwater chemical components was variable with concentrations descending from TDS > HCO3− > Ca2+ > NO3− > SO42- > Na+ > Cl− > Mg2+ > K+ > NO2− > NH4+. Notably, NO3− concentrations ranged from 0.02–492.72 mg/L and averaged 98.62 mg/L. Over 50% of samples exceeded the Quality Standard for Groundwater of China Class III N threshold (20 mg/L). Principal component analysis determined that NO3 contamination was primarily due to the excessive use of fertilizers in agriculture. A human health risk assessment model was used to assess the potential health risks of groundwater NO3− via drinking water and skin contact pathways. Approximately 90% of adults, 66% of children, and 45% of infants had acceptable health risks in the study area. NO3− exposure risk in the towns of Longjia and Xiyingcheng was the highest, while urban areas tended to have lower exposures. The health risks of residents, especially minors and infants, were concerned.

scholarly journals Assessment of Human Health Risks Posed by Nano-and Microplastics Is Currently Not Feasible

2020 ◽  
Vol 17 (23) ◽  
pp. 8832
Author(s):  
Andreas Brachner ◽  
Despina Fragouli ◽  
Iola F. Duarte ◽  
Patricia M. A. Farias ◽  
Sofia Dembski ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Human Health ◽  
Reference Materials ◽  
Chemical Reactivity ◽  
Health Hazard ◽  
Human Health Risk ◽  
Model Systems ◽  
Risk Assessments ◽  
Critical Parameters ◽  
Potential Health

The exposure of humans to nano-and microplastic particles (NMPs) is an issue recognized as a potential health hazard by scientists, authorities, politics, non-governmental organizations and the general public. The concentration of NMPs in the environment is increasing concomitantly with global plastic production and the usage of plastic materials. NMPs are detectable in numerous aquatic organisms and also in human samples, therefore necessitating a risk assessment of NMPs for human health. So far, a comprehensive risk assessment of NMPs is hampered by limited availability of appropriate reference materials, analytical obstacles and a lack of definitions and standardized study designs. Most studies conducted so far used polystyrene (PS) spheres as a matter of availability, although this polymer type accounts for only about 7% of total plastic production. Differently sized particles, different concentration and incubation times, and various biological models have been used, yielding hardly comparable data sets. Crucial physico-chemical properties of NMPs such as surface (charge, polarity, chemical reactivity), supplemented additives and adsorbed chemicals have been widely excluded from studies, although in particular the surface of NMPs determines the interaction with cellular membranes. In this manuscript we give an overview about the critical parameters which should be considered when performing risk assessments of NMPs, including novel reference materials, taking into account surface modifications (e.g., reflecting weathering processes), and the possible role of NMPs as a substrate and/or carrier for (pathogenic) microbes. Moreover, we make suggestions for biological model systems to evaluate immediate toxicity, long-term effects and the potential of NMPs to cross biological barriers. We are convinced that standardized reference materials and experimental parameters along with technical innovations in (nano)-particle sampling and analytics are a prerequisite for the successful realization of conclusive human health risk assessments of NMPs.

In Vitro to In Vivo Extrapolation (IVIVE) for human health risk assessment

2013 ◽  
Vol 221 ◽  
pp. S14
Author(s):  
R. Conolly ◽  
T. McMullin ◽  
R.N. Hines ◽  
L.P. Sheets ◽  
S.M. Cohen
Keyword(s):  
Risk Assessment ◽  
Health Risk ◽  
Human Health ◽  
Health Risk Assessment ◽  
Human Health Risk ◽  
Human Health Risk Assessment ◽  
In Vivo Extrapolation
Sign in / Sign up

Export Citation Format

Share Document