AGENDA
2010 HRL Rule Amendments ‐ Public Meeting
Wednesday, May 19, 2010
Red River Room
Snelling Office Park
Time 3:00 — 3:10 — 3:30 — 3:40 — 4:40 — 5:00 — 5:10 — 5:15 — Topic Welcome Overview of: 
Chemical Selection & Review 
2010 Amendments Q&A Session 2010 Chemicals & Draft HRL Values Q&A Session Overview of: 
Types of Guidance on Groundwater Contaminants 
Contaminants of Emerging Concern (CEC) Efforts Next Steps Wrap‐up Speaker Nitika Moibi Paul Moyer Helen Goeden Kate Sande Paul Moyer Christopher Greene Nitika Moibi Pamela Shubat The presentation will be followed by an information availability session in the St. Croix Room located in the Snelling Office Park. MDH staff will be available until 7 p.m. for additional questions. Amendments to the Health Risk
Limit (HRL) Rules on
Groundwater Contaminants
Minnesota Department of Health
Presentation at the HRL Rule Amendment
Public Meeting
May 19, 2010
Agenda
 About Rulemaking
 Overview of:
– Chemical Selection & Review
– 2010 Amendments
 2010 Draft HRLs & Chemicals
 Overview of:
– Types of Guidance on Groundwater Contaminants
– Drinking Water Contaminants of Emerging Concern
(CEC)
 Stay informed, Inform MDH
 Wrap-Up
2
HRL Public Meeting (May 19, 2010)
What is Rulemaking?
-Nitika Moibi, MPP
The Rulemaking Process
Statutory Rulemaking
Authority
Request for Comments
Rule & SONAR Development
Today’s meeting is to provide information
on amendments, answer your questions &
gather your input
Notice of Intent to Adopt
‘Dual Notice’
Administrative Law Judge
Review
Governor’s Office Review
HRL Public Meeting (May 19, 2010)
Rule Adoption
4
Health-Based Guidance for
Groundwater Overview
-Paul Moyer, MS
Today’s Presentation





2010 Draft HRL Chemicals
Chemical Selection
Background & History
Chemical Review Process
Draft HRL Values
6
HRL Public Meeting (May 19, 2010)
2010 HRL Rules Revision
 14 Chemicals added to 4717.7860
 26 Chemicals Deleted from 4717.7500 (93/94)
– “Housekeeping”
– Chemicals from 2009 Rules Revision
– Chemicals reviewed since
7
HRL Public Meeting (May 19, 2010)
2010 draft HRL Chemicals







Acetochlor ESA
Acetochlor OXA
Acetone
Dichlorodifluoromethane
1,1-Dichloroethene
Ethylbenzene
Ethylene glycol







Metolachlor
Metolachlor ESA
Metochlor OXA
PFBA
PFBS
Toluene
Xylenes
8
HRL Public Meeting (May 19, 2010)
Today’s Presentation





2010 Draft HRL Chemicals
Chemical Selection
Background & History
Chemical Review Process
Draft HRL Values
9
HRL Public Meeting (May 19, 2010)
Selection of Chemicals
 Continuation of “Commonly Detected”
– 2007 Water Level Standards
– Top 13 in 2009 HRL rules revision
 Next List of High Priority Chemicals
– Interagency Work Group
– Semi-annual meetings
10
HRL Public Meeting (May 19, 2010)
Solicited Program-Specific
Groundwater Information from MDH
– Drinking Water Programs
– Site Assessment & Consultation
 MPCA
– Ambient Monitoring Program
– Remediation Program
• Closed Landfill
• Petroleum
• RCRA
• Superfund
• Voluntary Investigation & Cleanup (VIC)
 MDA
– Incidence Response Program
– Pesticide Management Program
11
HRL Public Meeting (May 19, 2010)
Today’s Presentation





2010 Draft HRL Chemicals
Chemical Selection
Background & History
Chemical Review Process
Draft HRL Values
12
HRL Public Meeting (May 19, 2010)
Health-Based Guidance
 A Health Risk Limit is the concentration of a
contaminant, or mixture of contaminants, in
groundwater that is likely to pose little or no
risk to human health, including vulnerable
subpopulations, if consumed for one day or up
to a lifetime.
 Expressed as microgram (µg) of a contaminant
per liter (L) of water (e.g., 0.3 µg /L PFOS)
13
HRL Public Meeting (May 19, 2010)
History
 Groundwater Protection Act, 1989
– 1993/94 HRLs
 Health Standards Statute, 2001
 Additional legislation
– Water Levels Standard, 2007
– PFC expedited rule-making, 2007
 2008 (2009) HRL rules revision
 2010 HRL rule amendments
14
HRL Public Meeting (May 19, 2010)
Basis of Health Risk Limits
HRL (µg/L) ∝ (Toxicity) (Intake)
15
HRL Public Meeting (May 19, 2010)
Evolving Science
2001/2 – MDH Initiated Rules Revision
HRL (µg/L) ∝ (Toxicity) (Intake)
•Protective of sensitive life stages (e.g.,
developmental stage)
•Evaluation of less-than-chronic
durations
•Identification of highly exposed populations
• Updated Intake Data
16
HRL Public Meeting (May 19, 2010)
Evolving Science (continued)
 Toxicity Assessment
– 2002 EPA Review of the Noncancer Toxicity
Value Review Process
– 2005 EPA Guidance for Assessing Carcinogens
and Supplement on Early Life Exposure to
Carcinogens
– 2006 EPA Framework for Assessing Health Risks
of Environmental Exposures to Children
– 2008 California EPA Draft Air Toxics Risk
Assessment Guidelines (finalized May 2009)
17
HRL Public Meeting (May 19, 2010)
Evolving Science (continued)
 Intake Assessment
– 2004 EPA Estimated Water Ingestion in the
U.S.
– 2006 Draft EPA Child-Specific Exposure
Factors Handbook (finalized September
2008)
18
HRL Public Meeting (May 19, 2010)
2009 Rules Revision





Statutory mandates
Improved risk assessment methodology
New water intake data
New toxicological data
Additional contaminants
Apply methodology with a
focus on susceptible populations
HRL Public Meeting (May 19, 2010)
19
Today’s Presentation





2010 Draft HRL Chemicals
Chemical Selection
Background & History
Chemical Review Process
Draft HRL Values
20
HRL Public Meeting (May 19, 2010)
Health Risk Assessments
 Three Levels of Review
– Primary
• Information compilation
• Data evaluation
• Qualitative/Quantitative assessment
– Secondary
• Re-evaluation & assessment
• Discussion with primary reviewer
– Team Review
• Conclusions & rationale discussed
• Resolution of scientific judgment issues
21
HRL Public Meeting (May 19, 2010)
Information Compilation
 Data Types
– Human Epidemiology
– Mammalian animal studies
– In vitro assays
 Data Sources
– EPA
• NCEA / IRIS
• OPP / REDs
– ATSDR
• Toxicological Profiles
– California – OEHHA
• PHGs
– Peer-Reviewed Literature
22
HRL Public Meeting (May 19, 2010)
Information Compilation
 Data Organization / Considerations
– Exposure Durations
• Acute (up to 24 hr)
• Short-term (up to 30 days)
• Subchronic (up to 10% of a lifetime)
– ~90 days in rodents
– ~7 – 8 years in humans
• Chronic (> 10% of a lifetime)
– Health Standard Statute Endpoints
•
•
•
•
•
•
Developmental
Reproductive
Immunological
Neurological
Endocrine
Cancer
23
HRL Public Meeting (May 19, 2010)
Types of Studies




Developmental – dosing during pregnancy
Reproductive – male & female dosing
Multigenerational – parental dosing / offspring dosing
Repeated Dose Studies
– Short-term
– Subchronic
– Chronic / Cancer
 Specialty
–
–
–
–
Neurological
Immunological
Endocrine
Molecular / In vitro assays
24
HRL Public Meeting (May 19, 2010)
Study Design
 Oral
–
–
–
–
Gavage
Drinking Water
Dietary
Encapsulated
 Inhalation
25
HRL Public Meeting (May 19, 2010)
Data Evaluation
 Animals
– Species
– Number
 Dosing
– Number
– Range
– Spacing
 Interim time points
 Adequate controls
 Statistics
26
HRL Public Meeting (May 19, 2010)
Types of Studies
27
HRL Public Meeting (May 19, 2010)
Qualitative/Quantitative Assessment




Critical study selection
Point of Departure
Human Equivalent Dose (HED)
Uncertainty / Variability Factors (UFs)
–
–
–
–
–
Extrapolation from animal study
Human variability
LOAEL-to-NOAEL
Subchronic-to-Chronic
Database
 Reference Dose (RfD)
28
HRL Public Meeting (May 19, 2010)
Qualitative/Quantitative Assessment
 Noncancer
 Cancer
– Linear (Non-threshold)
• EPA cancer potency / slope factor
• Early-life adjustments
– EPA default approach
– Chemical specific
– Nonlinear (Threshold)
• Data shows a NOAEL exists
• RfD / Noncancer approach used
29
HRL Public Meeting (May 19, 2010)
Intake Rates
HRL (µg/L) ∝ (Toxicity) (Intake)
0.35
95th % Intake Rate (L/kg-d)
Acute (<1 day) & Short-term (>1 to 30 days)
0.3
0.25
0.2
0.15
Subchronic (>30 days up to <10% of lifetime)
0.1
Chronic (>10% lifetime up to lifetime)
0.05
2L/70 kg
65
+
yr
yr
-6
4
yr
55
-5
4
yr
25
-2
4
yr
20
15
-1
9
yr
4
-1
11
7
-1
0
yr
yr
4
-6
yr
-3
1
m
on
-<
12
m
on
6
3
-<
6
3
-<
1
bi
rth
-<
1
m
m
on
on
0
Age Group
30
HRL Public Meeting (May 19, 2010)
Protection of Shorter Durations
Final Comparison of Calculated Values
 Longer term nHRLs must be protective of high short
duration exposures. If a calculated longer term value was
higher than a shorter duration value the long term value was
set equal to the short-term value
31
HRL Public Meeting (May 19, 2010)
Today’s Presentation





2010 Draft HRL Chemicals
Chemical Selection
Background & History
Chemical Review Process
Draft HRL Values
32
HRL Public Meeting (May 19, 2010)
2010 draft HRL Chemicals
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




Acetochlor ESA
Acetochlor OXA
Acetone
Dichlorodifluoromethane
1,1-Dichloroethene
Ethylbenzene
Ethylene glycol







Metolachlor
Metolachlor ESA
Metochlor OXA
PFBA
PFBS
Toluene
Xylenes
33
HRL Public Meeting (May 19, 2010)
2010 draft HRL Chemicals
Value Increase







Acetochlor ESA
Acetochlor OXA
Acetone
Dichlorodifluoromethane
1,1-Dichloroethene
Ethylbenzene
Ethylene glycol







Metolachlor
Metolachlor ESA
Metochlor OXA
PFBA
PFBS
Toluene
Xylenes
34
HRL Public Meeting (May 19, 2010)
2010 draft HRL Chemicals
Value Decrease
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



Acetochlor ESA
Acetochlor OXA
Acetone
Dichlorodifluoromethane
1,1-Dichloroethene
Ethylbenzene
Ethylene glycol







Metolachlor
Metolachlor ESA
Metochlor OXA
PFBA
PFBS
Toluene
Xylenes
35
HRL Public Meeting (May 19, 2010)
2010 draft HRL Chemicals
Recent Guidance
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

Acetochlor ESA
Acetochlor OXA
Acetone
Dichlorodifluoromethane
1,1-Dichloroethene
Ethylbenzene
Ethylene glycol







Metolachlor
Metolachlor ESA
Metochlor OXA
PFBA
PFBS
Toluene
Xylenes
36
HRL Public Meeting (May 19, 2010)
Questions/Comments
HRL Public Meeting (May 19, 2010)
Metolachlor
Metolachlor ESA
Metolachlor OXA
Acetochlor ESA
Acetochlor OXA
Pesticides & Pesticide degradates
-Helen Goeden, PhD
METOLACHLOR (includes s-Metolachlor)
 Health Endpoints –
– Acute & Short-term: Developmental
– Subchronic & Chronic: None (decreased body weight in adults)
 3-fold increase from 1993/94 HRL value
– Cancer: Limited evidence – non-linear approach utilized
39
HRL Public Meeting (May 19, 2010)
METOLACHLOR
(includes s-Metolachlor)
 Database – 1 developmental study (rats); 1 – 2 generation
reproductive/developmental study (rats); 2 – 90 day studies (1 - rats
& 1 - dogs); 1-6 month study (dogs); 1-1 year study (dogs); and 2-2
year studies (1-rats & 1- mice)
 Cancer – Nonlinear Approach
– 1994 EPA IRIS classification – Group C carcinogen (“possible” human
carcinogen). 1993/94 HRL incorporated 10-fold adjustment
– 2006 EPA OPP assessment - recommended non-linear approach.
Tumors were observed in rats (but not mice) & only at the highest dose
level (150 mg/kg-d). No tumors were observed at the next lowest dose
(15 mg/kg-d). Chronic RfD (0.097 mg/kg-d) is sufficiently low to be
protective of cancer risk
40
HRL Public Meeting (May 19, 2010)
METOLACHLOR ESA & OXA
41
HRL Public Meeting (May 19, 2010)
METOLACHLOR ESA
 Health Endpoints – Liver system
 Slight decrease from 2004 HBV value
– Application of DB UF of 3 for lack of 2 generation study
– Lower water intake rate
42
HRL Public Meeting (May 19, 2010)
METOLACHLOR OXA
 Health Endpoints – None (clinical chemistry changes but unable to

identify specific target organ)
Slight decrease from 2004 HBV value
– Application of DB UF of 3 for lack of 2 generation study
– Lower water intake rate
43
HRL Public Meeting (May 19, 2010)
METOLACHLOR ESA & OXA
 Database for each consists of 1 developmental study
(rats) and 2 – 13 week studies (1 rats & 1 dogs)
– Short-term value was derived for OXA based on observations at
the 4 week assessment time point of the 13 week study
 Database UF for lack of 2 generation study
– 2 generation study identified lower NOAEL/LOAELs than
developmental study for acetochlor, alachlor & metolachlor. This
is a significant data gap
44
HRL Public Meeting (May 19, 2010)
ACETOCHLOR ESA & OXA
45
HRL Public Meeting (May 19, 2010)
ACETOCHLOR ESA
 Health Endpoint – Thyroid
 6-fold increase from 2006 HBV value
– Decreased subchronic-to-chronic UF from 10 to 3
– Lower water intake rate
46
HRL Public Meeting (May 19, 2010)
ACETOCHLOR OXA
 Health Endpoint – Thyroid
 2-fold increase from 2006 HBV value
– Selected lower NOAEL
– Decreased subchronic-to-chronic UF from 10 to 3
– Lower water intake rate
HRL Public Meeting (May 19, 2010)
47
ACETOCHLOR ESA & OXA
 Database for ESA - 28 day dietary study (rats) and 90
day dietary study (rats)
 Database for OXA - 1 developmental study (rats), 28
day dietary study (rats) and 90 day study (rats)
[no 2 generation study or dog study]
 OXA values 3-fold lower than ESA values
– Magnitude of effect on body weight and thyroid hormones was
greater
48
HRL Public Meeting (May 19, 2010)
Acetone
Ethylbenzene
Toluene
Xylenes
Volatile Organic Compounds
Common Source – Petroleum
-Kate Sande, MS
ACETONE
10000
9000
Micrograms per Liter (ug/L)
8000
7000
6000
5000
4000
3000
2000
1000
0
93/94 HRL
2010 Draft HRL


Acute
Short-term
Subchronic
9000
8000
Chronic
700
4000
Health Endpoints – Short-term-Kidney; Subchronic/Chronic-Kidney &
Blood
5-fold increase from 93/94 HRL
– Drinking water vs. gavage administration, drinking water more relevant
HRL Public Meeting (May 19, 2010)
50
ACETONE
2500
2328
Dose (mg/kg-day)
LOAEL
2000
1700
1500
0


900
Kidney
effects
Blood &
Kidney
effects
900
Blood &
Kidney
effects
Kidney
effects
500
100
↑
'10 Short-term, '10 Subchronic, '10 Chronic,Kidney
90- '93/94 Chronic,
14-day drinking 90-day drinking day drinking
Weight 90-day gavage,
water, rats
water, rats
water, rats
rats
Insufficient information to derive an acute value
Rats & humans metabolize acetone similarly


1485
1000
500
NOAEL
1700
Animal to human uncertainty factor = 3
1991 NTP study more thorough than 1986 American Biogenics Study

More acetone shunted to kidney by gavage
51
HRL Public Meeting (May 19, 2010)
ETHYLBENZENE
Micrograms per Liter (ug/L)
800
700
600
500
400
300
200
100
0
93/94 HRL
2010 Draft HRL
Calculated Value



Acute
Short-term
Subchronic*
50
50
50
100
Chronic*
700
50
70
Health Endpoints – Liver & kidney system
Subchronic & chronic defaulted to short-term duration
14-fold decrease from 93/94 HRL
–
–
Previous chronic value based on 1956 study conducted in only females and subset of endpoints
2010 value based a more current, 2007 study that looked at male & females & evaluated a wide
variety of endpoints
52
HRL Public Meeting (May 19, 2010)
TOLUENE
1200
Micrograms per Liter (ug/L)
1000
800
600
400
200
0
93/94 HRL
2010 Draft HRL
Calculated Value



Acute
Short-term
Subchronic*
200
200
200
600
Chronic*
1000
200
400
Health Endpoints – Immune & nervous system
Subchronic & chronic durations defaulted to short-term
5-fold decrease from 93/94 HRL
–
Intake rates & consideration of short-term duration
53
HRL Public Meeting (May 19, 2010)
XYLENES – o, m & p isomers
Micrograms per Liter (ug/L)
10000
1000
100
10
1
93/94 HRL
2010 Draft HRL
Calculated Value



Acute
Short-term
Subchronic*
800
800
300
300
300
400
Chronic*
10,000
300
800
Health Endpoints – Nervous (all durations) & kidney system (subchronic
and chronic)
Subchronic & chronic durations defaulted to short-term
33-fold decrease from 93/94 HRL
–
–
Consideration of short-term duration & intake rates
Critical study for 2010 subcrhonic & value different than that selected by EPA, IRIS for
chronic RfD value (same calculated chronic RfD)
–
Database uncertainty factor not applied to 93/94 HRL
–
Condie et al study selected as critical study by Canada (basis of TDI), Netherlands, & for EPA RED
54
HRL Public Meeting (May 19, 2010)
1,1,-Dichloroethene
Dichlorodifluoromethane
Ethylene Glycol
PFBA
PFBS
Organic Compounds
Halogenated / Other
-Paul Moyer, MS
1,1-DICHLOROETHENE
1,1-Dichloroethene
Micrograms per Liter (ug/L)
250
200
150
100
50
0
Acute
Short-term Subchronic
6
93/94 HRL
2010 Proposed HRL
Chronic
200
200
Non-cancer Duration
 Health Endpoints – Liver system
 33-fold increase from 93/94 HRL
56
HRL Public Meeting (May 19, 2010)
1,1-DICHLOROETHENE
 Database consists of a 3 generation study, a developmental study, 4
subchronic studies (e.g. 90 day), & 2 chronic studies
 Inhalation studies also have been conducted
 Acute/Short-term RfD
– No treatment related developmental or short-term effects were
observed at the doses tested
 Subchronic / Chronic
– Change in Point of Departure
– Use of BMD
 Cancer
– Data showing equivocal carcinogenicity by the oral route of exposure
are not sufficient to justify calculating an oral slope factor under the
draft revised cancer guidelines (EPA, 2002)
57
HRL Public Meeting (May 19, 2010)
DICHLORODIFLUOROMETHANE
Dichlorofluoromethane
Micrograms per Liter (ug/L)
1200
1000
800
600
400
200
0
Acute
Short-term Subchronic
Chronic
1,000
93/94 HRL
700
2010 Proposed HRL
Non-cancer Duration
 Health Endpoints – None
 1.4-fold decrease from 93/94 HRL
58
HRL Public Meeting (May 19, 2010)
DICHLORODIFLUOROMETHANE
 Small oral database - consisted of a 3 Gen study, a 90 day
study, & two 2 year studies
 Inhalation studies also have been conducted
 Acute / Short-term / Subchronic – Insufficient information
 Chronic RfD
– Same critical study as EPA, 1995, but different POD / UFs
– New methodology / intake rates
59
HRL Public Meeting (May 19, 2010)
ETHYLENE GLYCOL
Ethylene glycol
Micrograms per Liter (ug/L)
12000
10000
8000
6000
4000
2000
0
Acute
Short-term Subchronic
10000
93/94 HRL
2010 Proposed HRL
Chronic
4000
4000
2000
2000
Non-cancer Duration
 Health Endpoints – Developmental & Kidney system
 5-fold decrease from 93/94 HRL
60
HRL Public Meeting (May 19, 2010)
ETHYLENE GLYCOL
 Database consists of 4 developmental, 5 teratology, 2 repro, 1 3-gen, 6
subchronic (in mice & rats), & 6 chronic oral studies
 Metabolic Threshold
 Acute / Short-term RfDs
– developmental study by Neeper-Bradley et. al.,1995
– ATSDR calculated a BMDL for skeletal malformations, UF = 100
– Mother’s IR used, not infant IR
 Subchronic RfD
– 16 week dietary study by Cruzan et al 2004
– BMDL calculated for kidney effects, UF = 100
 Chronic RfD
– 12 month dietary study by Corley et al 2008
– NOAEL for kidney effects(NOTE - data was not amenable to BMD modeling), UF =
300
61
HRL Public Meeting (May 19, 2010)
PFBA
PFBA
Micrograms per Liter (ug/L)
12
10
8
6
4
2
0
2008 HBV
2010 Proposed HRL
Calculated Value
Acute
Short-term
Subchronic*
Chronic*
8
7
7
7
7
7
7
8
10
Non-Cancer Duration
 Health Endpoints – Liver system & thyroid (E)
 Subchronic /chronic durations defaulted to short-term
 No acute value in 2010 compared to 2008
62
HRL Public Meeting (May 19, 2010)
PFBA
 Database included an 8 day study, a 28 day study, a developmental
study, & a 90 day study
 Human data is available from worker biomonitoring studies for TK
comparisons and HED calculations
 Acute RfD = serum steady state no achieved with 24 hr exposure
 Short-term RfD
–
–
–
–
28 day study, NOTOX 2007
BMDL calculated for decreased cholesterol
Thyroid effects – co-critical
HED (BMDL divided by a half-life adjustment factor of 8 for extrapolation
from male rats to humans); UF = 100
 Subchronic and chronic draft HRLs defaulted to short-term duration
– Discussion about inclusion of developmental & hematological effects seen in
the 90 day study as Additivity Endpoints
63
HRL Public Meeting (May 19, 2010)
PFBS
Micrograms per Liter (ug/L)
PFBS
10
8
6
4
2
0
Acute
Short-term Subchronic
Chronic
Previous Guidance
2010 Proposed HRL
9
7
Non-cancer Duration
 Health Endpoints – Blood system, Liver system,
Kidney system
 New Value – 2009 HBV (no previous guidance)
64
HRL Public Meeting (May 19, 2010)
PFBS
 Database included a developmental, a 2-gen, a 10-day, a 28day, and a 90 day study
 Acute / Short-term – Not derived, steady state not achieved.
 Subchronic RfD
– 90 Day Oral Gavage Study by Leider et al 2009 and York 2003
– HED (Serum levels were not reported, therefore an administered dose
NOAEL divided by a half-life adjustment factor of 142 for extrapolation from
male rats to humans), UF = 100
 Chronic RfD
– Same Study / HED
– UF = 300
65
HRL Public Meeting (May 19, 2010)
Guidance Development at MDH
Chris Greene, MS
HRLs in Context
Development of guidance for groundwater is a
continuous process, punctuated by rulemaking
events
 Health-Based Values (HBVs)
 Risk Assessment Advice (RAA)
At rulemaking time, all non-promulgated
guidance values that can be taken into the
rulemaking process, are taken into the
rulemaking process
67
HRL Public Meeting (May 19, 2010)
HRLs in Context
A newer HBV or RAA takes precedence over an
older HRL, even though the HRL is promulgated
and the HBV or RAA is not
Upon promulgation, a HRL overrides any
preexisting HBV or RAA
It is always the more recent value that takes
precedence.
It is always the more recent value that takes
precedence
HRL Public Meeting (May 19, 2010)
68
HRLs in Context
On our website,
groundwater values of
all types are kept in a
single table
Users are advised to use
this table for the most
current values; HRL values
in the published Rule may
have been supplanted by
an HBV or RAA
69
HRL Public Meeting (May 19, 2010)
When Does MDH Develop New
Guidance?
 Other state agencies may request a value be
developed
 MDH may become aware of significant new
data that warrants a new evaluation
 A chemical may be identified as a priority
chemical under another program, such as
Drinking Water Contaminants of Emerging
Concern (CEC)
70
HRL Public Meeting (May 19, 2010)
CEC Overview
 “Emerging Concerns”: chemicals that have
the potential to impact drinking water, but for
which current guidance is outdated or
nonexistent
 Newly identified potential hazards
 Newly identified exposures
71
HRL Public Meeting (May 19, 2010)
CEC Overview
 MDH develops guidance using the same
methods as HRLs, HBVs, & RAA
 Unlike a HRL chemical, a CEC need not be
present in Minnesota Groundwater
 If a CEC IS present in Minnesota
groundwater, a CEC review may result in a
HRL during a future rulemaking
72
HRL Public Meeting (May 19, 2010)
CEC Evaluation Process
 Identify chemicals for review
 Assess potential exposure to the general
population, with a focus on drinking water
exposure
 Develop health-based guidance
 Communicate the exposure potential and
health-based guidance to the public
73
HRL Public Meeting (May 19, 2010)
CEC Selection & Screening
Chemical Selection
 Used in Minnesota
 Potential for migration to groundwater or surface
water
 Current guidance is old or nonexistent
Chemical Screening
 Environmental occurrence
 Likelihood of exposure
 Availability of toxicological data
74
HRL Public Meeting (May 19, 2010)
CEC Candidate List
FY 2010
 Triclosan
 1,2,3-Trichloropropane
 Metabolites of metribuzin
FY 2011
 Six chemicals undergoing screening
75
HRL Public Meeting (May 19, 2010)
CEC Chemicals
 6-Acetyl-1,1,2,4,4,7-hexamethyltetraline) (AHTN or
Tonalide)
– Polycyclic musk, fragrance in consumer products
 N,N-Diethyl-meta-toluamide (DEET)
– Insect repellent, consumer product
 Tri(2-chloroethyl)phosphate (TCEP)
– Flame retardant
 Propyl paraben
– Parabens, consumer products, food additive
 Carbamazapine
– Antiseizure pharmaceutical
 Pyraclostrobin
– Pesticide (fungicide) with significant new use and 3-fold
increased sales in MN over 5-yr period
76
HRL Public Meeting (May 19, 2010)
CEC Stakeholder Engagement
 Task Groups
– Peer review of the chemical evaluation
process
– Advise MDH on criteria
– Advise MDH on chemical nominations
 Contracted Work/Research Grants
 Communications
– Website
– GovDelivery email updates
77
HRL Public Meeting (May 19, 2010)
Inform Us
Statutory Rulemaking
Authority
Request for Comments
Rule & SONAR Development
Today’s meeting is to provide information
on amendments, answer your questions &
gather your input
Notice of Intent to Adopt
‘Dual Notice’
Official 30-day comment period
Administrative Law Judge
Review
Governor’s Office Review
HRL Public Meeting (May 19, 2010)
Rule Adoption
78
Stay Informed
 MDH’s e-mail subscription service
– Sign up
https://service.govdelivery.com/service/subscribe.html?code=MNMDH_39
 EH Webpages
– Groundwater Rules
http://www.health.state.mn.us/divs/eh/risk/rules/water/amendment.html
– DWCEC
http://www.health.state.mn.us/divs/eh/risk/guidance/dwec/index.html
 State Register Publications
 Contact Us
Rules: Nitika Moibi
DWCEC: Michele Ross
[email protected]
[email protected]
(651) 201-4907
(651) 201-4927
79
HRL Public Meeting (May 19, 2010)
Questions
Health Risk Assessment Unit
Environmental Health Division
Minnesota Department of Health
HRL Public Meeting (May 19, 2010)
HRL Public Meeting
Wrap-Up
- Pam Shubat, PhD
2010 HRL Rule Amendments ‐ Public Meeting Handout ‐ Index of Terms Used BMD: Benchmark Dose A dose or concentration that produces a predetermined change in the response rate of an adverse or
biologically meaningful effect. The BMD approach uses mathematical models to statistically determine
a dose associated with a predefined effect level (e.g., 10 percent).
BMDL: Benchmark Dose Lower Limit
A statistical lower confidence limit on the benchmark dose (BMD).
Default Duration Periods:  Acute duration: A period of 24 hours or less.  Short‐term duration: A period of more than 24 hours, up to 30 days.  Subchronic duration: A period of more than 30 days, up to approximately 10% of the life span in humans (more than 30 days up to approximately 90 days in typically used mammalian laboratory animal species).  Chronic duration: A period of more than approximately 10% of the life span in humans (more than approximately 90 days to 2 years in typically used mammalian laboratory animal species). HBV: Health‐Based Value
A type of MDH health‐based guidance that specifies the concentration of a groundwater contaminant
that can be consumed daily with little or no risk to health. HBVs are derived using the same algorithm
as HRLs but have not yet been promulgated as rules.
HED: Human Equivalent Dose
The human dose (for other than the inhalation routes of exposure) of an agent that is believed to induce
the same magnitude of toxic effect as the experimental animal species dose. This adjustment may
incorporate toxicokinetic information on the particular agent, if available, or use a default procedure.
HRL: Health Risk Limit
A type of MDH health‐based guidance that specifies the concentration of a groundwater contaminant,
or a mixture of contaminants, that can be consumed with little or no risk to health and which has been
promulgated under rule. A HRL is expressed as a concentration in micrograms per liter (μg/L).
LOAEL: Lowest Observed Adverse Effect Level
The lowest exposure level at which a statistically or biologically significant increase in the frequency or
severity of adverse effects is observed between the exposed population and its appropriate control
group.
NOAEL: No observed adverse effect level
An exposure level at which there is no statistically or biologically significant increase in the frequency
or severity of adverse effects between the exposed population and its appropriate control group.
‐ 1 ‐
RfD: Reference Dose An estimate of a daily oral exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects for a given exposure duration. It is derived from a suitable exposure level at which there are few or no statistically or biologically significant increases in the frequency or severity of an adverse effect between an exposed population and its appropriate control group. The RfD is expressed in units of milligrams of the chemical per kilogram of body weight per day (mg/kg‐day). RAA: Risk Assessment Advice A type of MDH health‐based guidance that evaluates potential health risks to humans from exposures to a chemical. Generally, RAA contains greater uncertainty than HRLs and HBVs due to limited availability of information. Based on the information available, RAA may be quantitative (e.g., a concentration of a chemical that is likely to pose little or no health risk to humans expressed in ug/L) or qualitative (e.g., a written description of how toxic a chemical is in comparison to a similar chemical). SF: Slope Factor An upper‐bound estimate of cancer risk per increment of dose that can be used to estimate risk probabilities for different exposure levels. A slope factor is usually expressed in units of cancer incidence per milligram of chemical per kilogram of body weight per day (per [mg/kg‐day] or [mg/kg‐
day]‐1). UF: Uncertainty Factor One of several factors used in deriving a reference dose from experimental data. UFs are intended to account for:  Interspecies UF ‐ the uncertainty in extrapolating from mammalian laboratory animal data to humans (denoted as 3A or 10A);  Intraspecies Variability Factor ‐ the variation in sensitivity among the members of the human population (denoted as 3H or 10H);  Subchronic‐to‐Chronic Factor (Use of a less‐than‐chronic study for a chronic duration) ‐ the uncertainty in extrapolating from effects observed in a shorter duration study to potential effects from a longer exposure (denoted as 3S‐to‐C or 10 S‐to‐C);  LOAEL‐to‐NOAEL (Use of a LOAEL rather than a NOAEL) ‐ the uncertainty associated with using a study in which health effects were found at all doses tested (denoted as 3L‐to‐N or 10 L‐to‐N); and  Database Uncertainty ‐ the uncertainty associated with deficiencies in available data (denoted as 3DB or 10DB). Environmental Health Division
Health Risk Assessment Unit
651-201-4899
[email protected]
‐ 2 ‐
Health Risk Limit (HRL) Rule Amendment Public Meeting
Questions and Answers
May 2010
{Note: The following questions were asked during the Health Risk Limit (HRL) Rule Amendment Public Meeting on May 19, 2010. The answers noted below include and expand on the information staff presented at the meeting.} Q: What criteria do you used to determine the NOAEL/LOAEL? A: No observed adverse effect level (NOAEL) is typically identified as the dose level at which there is no statistically or biologically significant increase in the frequency or severity of adverse effects between the dosed animals and controls. Q: (follow‐up) How do you determine what is adverse? For example, if liver hypertrophy is observed but no changes in liver enzymes or histology are observed at that dose or higher doses would you consider that adverse? A: Liver hypertrophy (i.e., increased liver weight) changes can represent an adaptive response. If the toxicity study included a variety of liver assessment parameters (i.e., liver enzymes were evaluated, complete histopathological assessment was conducted) and only hypertrophy was observed, even at higher doses, this observation alone would not be considered adverse. Hypertrophy can be an early indicator of insult. If increased liver weight was observed but histopathological changes were evident at the higher dose levels, if increased liver weight occurred at the highest dose level tested, or if additional parameters were not evaluated (e.g., no histopathology evaluation, no liver enzyme assessment) the effect could be considered to a “minimal” adverse effect. [Note: 2008 SONAR glossary defines an adverse effect as a biochemical change, functional impairment, or pathologic lesion that affects the performance of the whole organism or reduces an organism’s ability to respond to an additional environmental challenge. This definition is from the United States Environmental Protection Agency (EPA) document titled ‘Review of the Reference Dose and Reference Concentration Process’ (2002) and EPA’s Integrated Risk Information System (IRIS) Glossary of Terms, and is similar to the definition used by the Agency for Toxic Substance and Disease Registry (ATSDR) as well.] Q: What criteria do you use to determine when a database deficiencies uncertainty factor is applied? A: MDH uses the US EPA’s Review of the Reference Dose and Reference Concentration Process (2002) recommendations as guidelines for assessing areas of uncertainty [in particular see Section 4.4.5.1 Recommendations for Application of Uncertainty Factors]. For example, a database uncertainty factor (DB UF) is typically applied if a development or a 1
multi‐generation reproductive study is missing. We evaluate the database in a holistic manner. For the pesticide degradates included in the amendments, the lack of a 2 generation study was identified as a critical data gap for this group of chemicals. As a result, a DB UF was incorporated into the derivation of the reference dose. An example is the case of PFBA where we did not apply a DB UF for the lack of a multi‐generation study because the developmental study that was conducted was an extended one generation study that supplied the relevant information. Q: What is the function of parabens as a food additive? A: Parabens are added to foods for their antimicrobial properties. Q: How were the criteria for selecting chemicals for the Drinking Water Contaminants of Emerging Concern (CEC) program weighted? A: The selection criteria (see slide 74 of meeting presentation) included consideration of environmental occurrence (e.g., frequency and magnitude of detections), likelihood of exposure (e.g., potential to migrate to groundwater or surface water or has been found in drinking water sources), and availability of toxicological information. In addition MDH staff consulted with staff from other state and federal (e.g., USGS) agencies. Selected chemicals also meet one or more of the definitions and criteria of contaminants of emerging concern. The criteria were given approximately equal, qualitative weight. Additionally, for the first biennium of the program, MDH chose to select a variety of chemicals (pesticides, pharmaceuticals, industrial chemicals, etc.). The proposed stakeholder process includes the formation of a task group that would assist MDH in determining appropriate screening criteria and developing a prioritization or weighting scheme that can form the basis of decision tree or process for chemical selection. Q: What is the anticipated date of the SONAR? A: The SONAR is anticipated to be completed by the end of June, after which the Notice of Intent to Adopt the rule will be published in the State Register. Once the Notice of Intent to Adopt the rule is published, a 30‐day public comment period will begin. Rule updates will be available via MDH’s groundwater rules webpage and the e‐mail subscription service. Environmental Health Division Health Risk Assessment Unit 651‐201‐4899 [email protected] 2
Minnesota Department of Health Fact Sheet
May 2010 Drinking Water Contaminants of
Emerging Concern Program
Background
The constitutional amendment approved by
Minnesota voters in November 2008 dedicated
funding to the Clean Water Fund (CWF) to
protect, enhance, and restore water quality in
lakes, rivers, streams, and groundwater. Five
percent of the funds are targeted to protect
drinking water, a portion of which has been
allocated to the Minnesota Department of
Health (MDH). This funding made it possible
for MDH to establish the Drinking Water
Contaminants of Emerging Concern (CEC)
program which takes a proactive approach to the
protection of drinking water through research
and assessment of the potential public health
risks associated with contaminants of emerging
concern.
About the Program
The CEC program is tasked to identify
contaminants of emerging concern that have the
potential to impact Minnesota drinking water; to
investigate the potential for human exposure to
these contaminants; and to develop guidance
values, as applicable. The CEC program will
develop health-based guidance for ten
contaminants during the current biennium, three
in the first, and seven in the second fiscal year.
Contaminants evaluated under the CEC program
may include industrial chemicals, pesticides,
pharmaceuticals, personal care products, and
other contaminants that have been released or
detected in Minnesota waters (surface water and
groundwater) or that have the potential to
migrate to or be detected in Minnesota waters.
Chemical Reviews and Exposure Assessments
The three contaminants being evaluated this
fiscal year are 1,2,3-tricholoropropane (volatile
Environmental Health Division
625 Robert Street North, PO Box 64975
St. Paul, MN 55164-0975
651-201-4571
www.health.state.mn.us
organic compound), triclosan (antibacterial),
and three metribuzin (herbicide) degradates.
MDH staff have prepared environmental
exposure summaries and are developing healthbased values for these chemicals consistent with
current MDH risk assessment methodology.
Communication and Outreach
The work of the program will be facilitated by
developing collaborative relationships with
other state and federal agencies, academic and
industry researchers, and nonprofit groups.
MDH staff have conducted small group
meetings with partners from various state and
federal agencies and the University of
Minnesota and will be conducting similar
meetings with staff from various nonprofit and
industry stakeholder groups.
Research and Special Projects
Approximately half of the funds for CEC will be
used to contract research on the risks, toxicity or
occurrence of contaminants. MDH staff have
initiated a project to identify, evaluate, and
apply alternative risk assessment methodologies
to contaminants of emerging concern. The
project proposes to maximize the ability to
develop health based guidance when lack of
toxicological data limits the use of MDH’s
current risk assessment methodology.
For More Information
Additional information is provided at:
www.health.state.mn.us/divs/eh/risk/guidance/d
wec/index.html. To participate in upcoming
meetings or to be added to the program’s email
subscription service, please contact Michele
Ross at (651) 201-4927 or
[email protected].