Fabric Biocides
One client of The Sapphire Group developed a product that could be
applied to fabrics, carpets, and cloth-covered home furnishings to
prevent the growth of disease-bearing organisms. The product was
part of this client's
long-range plans and an important part of the company's
profit structure. Facing the long road toward approval by stringent
regulatory agencies, the company asked The Sapphire Group to assist
them in showing these agencies the value of and need for their
biocide.
Vinyl Chloride
Using physiologically-based pharmacokinetic (PBPK) modeling,
one of the principals of The Sapphire Group took on a re-evaluation
of the cancer slope factor (SF) assigned to vinyl chloride by the
US EPA.
Chlorinated Byproducts
The scientists at The Sapphire Group worked with the
Chlorine Chemistry Council to review an epidemiological study that
examined the relationship between chlorinated byproducts (DBPs) and
spontaneous abortions. Our experts broadened the study parameters to
encompass all that was known about possible reproductive impairment
and birth defects associated with DBPs.
Evaluation of Exposure Assessment Techniques
On behalf of the American Chemistry Council (ACC), The Sapphire
Group carried out a critical review and evaluation of
state-of-the-art techniques, tools, and approaches used in
conducting Exposure Assessments. The results of this effort were
published in a three volume report used by ACC in making long-term
research decisions and assessing the quality of exposure assessments
submitted by member companies or consultants.
Estimation of Risk
to Workers from Creosote Exposure
In assisting a client with reregistration under FIFRA, some of the
challenges presented in examining the risk to workers revolved
around the product being a complex mixture and the issue of dermal
and respiratory exposure to the components of the mixture based on
workplace exposure and physical-chemical properties. Also critical
to our
success in addressing the client's
concerns was the innovative manner in which our team effectively used the
highly detailed exposure data the industry had collected.
Voluntary Children's
Chemical Exposure Program (VCCEP)
The Sapphire Group prepared an exposure assessment for a client
under the VCCEP. The team reviewed published and unpublished
literature for exposure data that would be directly relevant to
children. Using a combination of fate and transport modeling,
published and unpublished data on 1,4-dioxane in consumer products
and foods in addition to environmental sources, child-specific
exposure factors, and internal dosimetry estimates, child-specific
exposure to 1,4-dioxane was estimated for relevant media and
exposure pathways. These were then combined with relevant
1,4-dioxane toxicity criteria to develop estimates of childhood
risks. The results of our assessment indicate that 1,4 dioxane is
unlikely to pose significant risks to children.
Dietary Exposure
to Environmental Pollutants
The Sapphire Group has
prepared a number of assessments involving the importance of diet in
exposure to contaminants. For example, studies have been conducted to
determine the actual intake of sport or subsistence fisherman along
contaminated bodies of water as an alternative to using default
consumption values developed by US EPA. Using interview techniques and
creel surveys, study subjects provided information on consumption of
fish, frequency, and preparation methods. These studies suggested that
the default sport fish consumption rate used grossly over-estimated the
amount of fish consumed and distorted the resultant risk estimates
accordingly. Similar studies have been undertaken to examine other
critical default exposure assumptions regarding diet or other exposures
used by the EPA in risk assessment following a sensitivity analysis to
identify those that contributed most significantly to the risk
estimates, and alternative site-specific values proposed in their place.
Applied Exposure Studies
The Sapphire Group has employed applied research to assess
whether presumed exposure has actually occurred and its significance to
body burden and risk in several instances. Studies of the relationship
between soil and dust levels of persistent pollutants (e.g., lead,
cadmium, arsenic, PCBs, DDT, chlordane, etc.) and blood or tissue levels
have indicated that these sources are not significant contributors to
body burden and risk. Similar studies of dietary sources, indoor air,
and water to exposure and body burden have also provided better
understanding of their relative contributions and provided specific data
to replace default assumptions with good results. Biomonitoring results
can influence the selection of absorption factors and provide the basis
for use of internal dosimetry in making more accurate estimates of risk.
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