Regulatory Policy Implications of 1,4-Dioxane - Environmental Investigation and Remediation - page 478

cells demonstrated a 50% uptake of the doughnut, while human ovarian cancer cells had an 18%
uptake rate. Researchers injected the doughnuts into mice tail veins and, within 4 h, the doughnuts
had all migrated to the mouse livers, causing no adverse effects. The doughnuts thus appear to be
ideally suited to delivering drugs or other agents to the mouse liver and may provide utility for in
vivo organ-specii c toxicity testing (Alexander et al., 2008; Royal Society of Chemistry, 2008).
10.8 REGULATORY POLICY RECOMMENDATIONS FOR ADDRESSING
1,4-DIOXANE RELEASES
The following regulatory policy recommendations are made for consideration by regulators and
regulated parties with the goal of applying a consistent set of regulations and response priorities to
effectively deal with 1,4-dioxane releases in a manner commensurate with the risks to human health
and the environment:
1. Fund studies to further improve and validate PBPK models by performing mechanistic
studies (possibly including in vitro and “omics” studies) to further the understanding of
1,4-dioxane mode of action for cancer in animals, focusing on the human relevance of
animal cancer data.
2. Prioritize screening-level site investigations for 1,4-dioxane at vapor degreasing sites, sol-
vent recycling sites, cement kilns that used waste solvents for fuels, and at landi lls that
received scintillation counting wastes (e.g., university landi lls * ).
3. Include 1,4-dioxane as a routine analyte for public water supply well sampling programs
where facilities that used or created 1,4-dioxane as a by-product overlie the well's capture
zone.
4. Test public water supply wells for 1,4-dioxane where methyl chloroform or its breakdown
products (1,1-dichloroethylene and 1,1-dichloroethane) have been detected.
5. Test for 1,4-dioxane in private wells located near potential sources of 1,4-dioxane.
6. Test recycled water for 1,4-dioxane before starting indirect potable reuse projects.
7. Test for 1,4-dioxane at sites where MNA has been approved for solvent remediation.
8. Fund the 1,4-dioxane remediation research initiatives suggested in Section 10.4.4 .
9. Run the gas chromatographs and MSs in open-scan mode, and report all TICs in samples
from both cleanup sites and drinking water systems.
10. Fund exploratory research that can be used to anticipate future environmental issues to
fuli ll the promise of Green Chemistry (see Section 10.7 ).
11. Revisit the causes of solvent and 1,4-dioxane contamination of groundwater in the United
States and Europe, and evaluate whether similar practices are now employed in offshore
manufacturing operations in countries whose regulatory framework does not yet address
these causes or prevent groundwater contamination by solvents and 1,4-dioxane.
The sources of funding to implement these recommendations must overcome the funding-source
dilemma of implied conl ict of interest when studies are funded and conducted by the producers of
the subject chemicals. One way to do this is to establish a pool of funds from industry and govern-
ment to perform basic, independent research administered by governmental agencies with oversight
by panels of independent experts including representatives of industry, regulatory agencies, aca-
demic institutions, and potentially impacted parties such as water purveyors, citizen groups, and
environmental groups.
* As described in Chapter 2, landi lls on university campuses or landi lls receiving wastes from universities and other
institutions with research laboratories are likely to have scintillation counting wastes and other laboratory wastes that
include 1,4-dioxane.