Toxic substances control act polychlorinated biphenyls Hanford site users guide

2003 ◽  
Author(s):  
A L PRIGNANO
2019 ◽  
Author(s):  
Chem Int

Polychlorinated Biphenyls (PCBs) in the vicinity of transformers soils at main campus of university of Port Harcourt, Choba, Nigeria was monitored. Evaluation was done for both total PCBs (Aroclor) and congener’s form using Gas Chromatography at four designated sites; A, B, C, and D with geographical co-ordinates for site A-Donald Ekong Library, latitude 4°54’, 32’’N and longitude 6°55:05’’E, site B-Senate building with latitude 4°54’14’’N and longitude 6°55’, 23’’N, site C-Transformer close to music department with latitude 4°54’, 01’’N and longitude 6°55; 56’’E and finally site D-Gana-Ma Lecturers residential quarters with latitude 4°54’.23’’ N and longitude 6°55’, 74’’E. All the sites are polluted with PCBs that exceeds the maximum limit of 2.0 mg/kg as per United States Toxic Substances Control Act (TSCA). The order of total PCBs was site D site > site A > site B > site C, which also corresponds with the order of sites carcinogenicity of dioxin-like PCBs, calculated as Total toxicity Equivalence concentration (TTEC). The TTEC for site A, B, C and D corresponds to 0.000012, 0.000035, 0.0000185 and 0.00039 (mg/kg), respectively, which exceeded the method B clean up levels for 2, 3, 7, 8-tetrachloro dibenzo-p-dioxin levels of 1.3×10-5 mg/kg and need of massive cleanup for carcinogenic dioxin-like PCBs. We also found out there is high loadings of PCBs congeners with little or no biodegradability across the four sites. To mitigate the known human health risks posed by PCBs toxicity, non-PCBs transformers should be replaced with current ones and extensive soil remediation is needed to clean up the PCBs to avoid negative impact.


1999 ◽  
Vol 01 (03) ◽  
pp. 329-347 ◽  
Author(s):  
REBECCA A. EFROYMSON

The Toxic Substances Control Act (TSCA) is the legislation used by the U.S. Environmental Protection Agency to regulate releases of genetically engineered microorganisms. The rule defining the scope of the notification requirements for releases of microbial products of biotechnology was published in April 1997. The Environmental Protection Agency (EPA) had some latitude regarding the extent to which various categories of microorganisms would be regulated, but the agency was constrained by requirements of TSCA and an interagency agreement about how to regulate products of biotechnology. This paper investigates the extent to which the scope of oversight is based on risk. A risk-based rule is defined as one where the reporting requirements are based on potential for exposure or expected adverse effects. The evolution of the rule is described, and risk-based components are discussed. In conclusion, the scope of oversight of microbial releases is determined to be based on risk to the extent that legislation and institutional constraints permit.


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