of Massachusetts Department ENVIRONMENTAL PROTECTION The Occurrence, Health Effects & Regulation of Perchlorate in Massachusetts Tsedash Zewdie Office

of Massachusetts Department

ENVIRONMENTAL PROTECTION

The Occurrence, Health Effects & Regulation of Perchlorate in

Massachusetts

Tsedash ZewdieOffice of Research & Standards

Massachusetts Department of Environmental Protection

tsedash [email protected]://mass.gov/dep/water/drinking/percinfo.htm



Acknowledgments

• ORS: Carol Rowan West, C. Mark Smith, Michael S. Hutcheson, Diane Manganaro

• MassDEP/MADPH Advisory Committee On Health Effects

• Staff of MassDEP’s Drinking Water Program and Bureau of Waste Site Cleanup



Topics

I1. Background information

2. Health effects and standard setting3. Differences in standard setting between regulatory

agencies4. Conclusions

II1. Occurrence of perchlorate in MA drinking water supplies

– Sources– Case studies

2. Conclusions



What is Perchlorate?

• Anion consisting of chlorine

and oxygen (ClO4-)

• Most common form is ammonium perchlorate

• Highly soluble and dissociates to give ClO4-

• Migrates to groundwater & stable in water for years



Rocket Fuel

Uses of Perchlorate

Flares

Fireworks

Military Weapons

Blasting Agents

Most Familiar Uses:



In The Beginning, There Was MMR...

• 2000 – Perchlorate detected on-base (500 g/L)

• 2002- Perchlorate detected in Town of Bourne production wells at low (< 1 µg/L)

• No federal or state drinking water standard

• MassDEP set an interim drinking water guideline

(www.mmr.org)



MADEP Drinking Water Guideline

• 1 µg/L for sensitive subgroups:• pregnant and nursing women• fetus, infant and young children • individuals with hypothyroidism

• Showering at low concentrations OK



• MassDEP decided to establish MCL in 2003• MassDEP issued its draft report for public review in 2004

(1 g/L). • NAS Panel established RfD of 7 x 10-4 mg/kg/d (2005)• US EPA used NAS RfD and derived a DWEL of 24.5 g/L

(2005)• CA EPA and NJ proposed to set DWLs at 6, and 5 g/L

respectively• National drinking water standard is years away, if ever • MassDEP took NAS results into account to to derive RfD

and MCL

Federal and State Activities on Perchlorate (2003 –2005)



Health Effects Assessment



NIS

Perchlorate Mode of Action

I-

vsClO4-

I-

ClO4-

POI

TGIodinated

thyroglobulin

EnzymesT4,T3T4, T3

Stroma Thyroid cell Colloid

NIS =Sodium Iodide Symporter

PO =Peroxidase enzyme

TG = Thyroglobulin

IE = Iodinase enzyme

Enzymes = lysozymes and proteases

Pendrin

Essential for metabolism, growth and development

IE



Observed Downstream Effects

• Altered Thyroid and Pituitary Hormones

• Thyroid Histopathy – colloid depletion, hypertrophy and hyperplasia, goiter

• Developmental Effects – brain morphometry changes, behavioral effects

• Tumors and tumor promotion



Standard Setting



MA Perchlorate Reference Dose (RfD)

• MassDEP evaluated available animal and human data, and put more emphasis on a human iodide uptake inhibition study (Greer et al. 2002)

0.007 mg/kg/d (LOAELhuman IUI)

100 (Uncertainty Factor)

= 7 x 10-5 mg/kg/d

RfD =



MA MCL Development Used RfD and considered:

• Exposure parameters: 70 kg person drinking 2 L of H20

• RSCF of (0.2) (food being major source)

• Calculated drinking water level = 0.49 g/L

• Considered other factors (occurrence and level in water supplies and source, ability and costs to treat, health impacts) to determine MCL

• First in the Nation MA MCL (2006) = 2 g/L

• NSF (2006) study indicated levels of perchlorate in treated drinking water could be 2 g/L or higher



Known Sources of Perchlorate Exposure

Emerging Information (2003) Research is Ongoing

• Lettuce 0 - 6,900 g/kg

• Cow’s Milk 0 - 11 g/L

• Breast Milk 1.4 - 92 g/L



State/Agency

POD (mg/kg/d)

Basis UF RSC (%)

RfD (mg/kg/d)

DWL (g/L)

MA 0.007 (LOAEL) Greer et al., 2002

10010 = Hum. Var.

3 = LOAEL Adj.

3 = Dbase def

20 7 x 10-5 0.4*

USEPA 0.007 (NOEL) Greer et al., 2002

10 7 x 10-4 24.5

CA 0.0037 (BMDL) Greer et al., 2002

10 60 3.7 x 10-4 6

NJ 0.0037 (BMDL) Greer et al., 2002

10 20 3.7 x 10-4 5

Comparison of Perchlorate Drinking Water Levels (DWL)

*MA final drinking water standard (MCL) was 2 g/L after consideration of other factors (occurrence and level in water supplies, ability and costs to treat, health impacts)



Urinary Perchlorate and Thyroid Hormone Levels in Adolescent and Adult men and women

Living in the USA (Blount et al., 2006)

• Performed one of a kind study correlating urine perchlorate with serum T4 and TSH

• Perchlorate was a significant predictor of T4 and TSH levels in iodine deficient women

• Perchlorate was a significant predictor of TSH in iodine sufficient women

• Perchlorate was not a significant predictor of T4 and TSH in men



Predicted Change in Serum Thyroxina and Serum TSHb levels from changes in urinary perchlorate levels, women aged 12 and older, with urine iodine <

100 g/L, NHANES 2001-2002Change in Urine Perchlorate Change in

(0.19 g/L is minimum level measured ) thyroxin (gdL)

Initial TSH Initial TSHof 1.40 IU/L of 3.11 IU/L

(50th percentile) (90th percentile)

0.19 to 0.65 mg/L (5th percentile) 0.48 0.23 0.51






0.19 to 13 mg/L (95th percentile) 1.64 0.95 2.210.19 to 100 mg/L (maximum) 2.43 1.63 3.61

aNormal range for thyroxin 5-12 g/dl

bNormal range for TSH: 0.3-4.5 IU/L

Change in TSH (IU/L)Depends on initial TSH level



Perchlorate Exposure and Thyroid Function in California Neonates; Infant Characteristics versus Perchlorate Levels in

Drinking Water (Schwartz, 2001)

Perchlorate ConcentrationNone

(0 ppb)

Low

(1-2 ppb)

Medium

(3-12 ppb)

High

13 ppb

Test stat p

Value (df)

No. of infants 255,382

(49.5)

127,041

(24.6)

131,483

(25.5)

1,945

(0.4)

Female, % 48 48.8 49 49

T4 mg/dL)

Mean (SD)

179.9

(50.9)

162.1

(48.7)

160.6

(48.3)

150.5

(44.0)

F = 1649.6

P <0.001 (3)

TSH, (U/mL)

Mean (SD)

7.6

(18.8)

7.6

(19.8)

7.7

(19.4)

7.9

(4.6)

F = 0.05

P = 0.9 (3)SD = Standard deviation; df = degree of freedom



Conclusions

MassDEP:

• took the weight of evidence approach in evaluating the toxicity of

perchlorate

• used human data accounting for all possible uncertainties in the database for standard setting

• considered various factors and set the MCL at 2 g/L



Perchlorate Occurrence in MA Drinking water, Sources, and Case

Studies



Perchlorate Occurrence MonitoringDetections (> 1 µg/L) March 2004 – February 2005

(approximately 700 systems)



MA DEP Follow-Up Investigations

• Site specific investigations private well sampling conducted by MADEP near contaminated public supply wells...

• Testing and evaluation of suspected source materials and activities.



Source Discovery

• Fireworks

• Blasting

• Sodium Hypochlorite

• Industrial Discharges



Fireworks

Perchlorate use and content has increased over time

Primary uses are to produce color effects and loud bang/flash

Potential Environmental Release PathwaysAtmospheric falloutDudsMisfires

• Sodium Hypochlorite



Water Supply Wells0.44 to 8.9 g/L

Chesterfield, MA

Perchlorate inPublic Water Supply Well, Private Wells, andFireworks Display Location



ANFO

95,000 LBS

Slurran XLS (SEC)

9,500 LBS

20-30 % Ammonium Perchlorate

Westford, Mass



Westford, MAConstruction of new municipal highway garage

Perchlorate inPublic Water Supply Well



Westford, MA

Perchlorate inPublic Water Supply Well andFireworks Display Locations



Westford, MA

Perchlorate inPublic Water Supply Well,Fireworks Display Locations and Blasting Site



Blasting

Blasting is locally regulated(harder to get handle on state-wide activities)

DEP worked with Department of Fire Services and Fire Marshall (http://mass.gov/dfs) to draft a letter to blasting contractors and interested parties(http://www.mass.gov/dep/bwsc/files/blasting.htm)

Perchlorates used as a sensitizer in a relatively small percentage of blasting agents and explosives; primarily water gel and emulsion formulations



ANFO: 621,000 LBS

Detagel: 360 LBS (?)

“< 7% Ammonium Perchlorate”

Blasting Caps: EZ-Det

0.5% Potassium Perchlorate (?)

Millbury, MA



The Merrimac River

•Hits greater than 1 µg/L in Surface Water Supply (Tewksbury)

•DEP conducted source investigation:

–Ambient sampling of Merrimac and Concord Rivers

–Influent, Process & Effluent sampling of WWTPs

–Mapping & sampling of sites, facilities and other sources along the rivers

–Concurrent sampling using IC and LC/MS/MS



Perchloric Acid DischargeConcord and Merrimack Rivers, MA

Tewksbury, MA

1-3 g/L in the public water supply system in Tewksbury

Public water supply system draws water from the Merrimack river



Industrial Discharges and Hypochlorite

• Perchloric acid is a powerful oxidizing agent

• Industrial-scale discharges of process wastewater have the potential to create significant impacts to groundwater and surface water

• Perchlorate is present in hypochlorite solutions used in commercial and household applications



Commercial Hypochlorite Products

Plant Brand

Perchlorate (g/L)

LC/MS/MSLowell WWTP Univar 3400

Lowell WWTP Jones 260

Billerica WWTP Univar 4600

Tewksbury WTP Univar 4100



Commercial Hypochlorite Product – Storage Study

Age Storage

Perchlorate (g/L) LC/MS/MS

New Just Delivered N.D.

26 Days Cool (5C) 995/1020

26 Days Filtered (5C) 490

26 Days Room Temp 6750



Brand Brand InfoPerchlorate g/L

LC/MS/MS

Chlorox 6% NaOCl 370

Shaws 2.5 years old 8000

Market Basket

6% NaOCl 390

Walmart 6% NaOCl 89

Household Bleach



Perchlorate Occurrence MonitoringMarch – October 2004 - Public Water Supply Data Only (693 systems)

Town

Maximum

(µg/L) Source?

Boxboro 1,300 Blasting

Chesterfield 8.9 Fireworks

Hadley 3.8 Unknown

Millbury 45 Blasting

Southbridge 3.1 Unknown

Tewksbury 3.3 Industry

Westford 3.7 Blasting

Westport 3 Fireworks

Williamstown 10 Fireworks



Conclusions• Occurrence monitoring data may prompt

regulation of disinfecting products nationally• Perchlorate contamination is not pervasive in Massachusetts• Localized impacts exist and present risks

• Most significant Sources of GW contamination:

–Military use (hundreds of µg/L)

–Blasting (tens-to-hundreds of µg/L)

–Fireworks (up-to-tens of µg/L)



For More Information…http://Mass.Gov/dep

Documents

of Massachusetts Department ENVIRONMENTAL PROTECTION The Occurrence, Health Effects & Regulation of Perchlorate in Massachusetts Tsedash Zewdie Office