Connections between Environmental ChemistryConnections between Environmental Chemistry Research and...

Department of Toxic Substances Control Cal/EPA

Connections between Environmental Chemistry Research and DTSC’s Safer Consumer Products

Program: A case study on Quaternary Ammonium Compounds (QACs).

Anne-Cooper Doherty, Ph.D.

Safer Consumer Products Program

April 8, 2015

Outline

DTSC’s Safer Consumer Products Program

SCP program research needs

Case Study: QACs research and SCP research needs

2

CALIFORNIA SAFER CONSUMER PRODUCTS PROGRAM (SCP)

3

Basics: The Goal: Safer consumer products

Asks the questions: • Is this chemical necessary? • Is there a safer alternative?

Greater market opportunities

for innovative companies

Basics: How the SCP Program Works

5

Candidate Chemicals List

Priority Products

Alternatives Selection

4. Regulatory Response

3. Alternatives Analysis

2. Products (Product-Chemical Combinations)

1. Chemicals

1100 Candidate Chemical Groups 23 Authoritative Lists referenced

• 8 exposure potential lists (NHANES, Cal Biomonitoring)

• 15 hazard trait lists

Exclusions

• Registered pesticides

• Prescription drugs

• Metabolite/breakdown products

• Radioactive chemicals

• Natural toxins

Updates with Authoritative Lists 6

>2,300 Chemicals http://www.dtsc.ca.gov/SCP/ChemList.cfm

Basics: Prioritization Principles for Picking Product/Chemical Combinations

Potential exposure to the Candidate Chemical(s) in the product

AND

Potential for exposures to contribute to or cause significant or widespread adverse impacts*

7 *adverse environmental impacts alone are sufficient

Initial 3 Priority Products Selected

8

Children’s Foam-Padded Sleeping Products containing TDCPP/TCEP

Paint Strippers containing Methylene Chloride

Spray Polyurethane Foam Systems with MDI

Next 3 Years: Priority Product Work Plan

Identify product categories for next 3 years

Provide market signals

Engage stakeholders, gather data

Identify potential Priority Products

9

Policy priorities

Clear exposure pathways (dermal, inhalation, etc.)

Biomonitoring results

Chemicals found in indoor air monitoring

Sensitive subpopulations – children, workers

Aquatic resource impacts and/or found in water quality monitoring

10

7 Product Categories

1. Beauty, Personal Care and Hygiene Products

2. Building Products - Paints, Adhesives, Sealants, Flooring

3. Household/Office Furniture/Furnishings

4. Cleaning Products

5. Clothing

6. Fishing and Angling Equipment

7. Office Machinery Consumable Products 11

SCP Research Needs

Monitoring data (including California specific) • Aquatic environments, indoor environments,

sensitive subpopulations

Contaminant source information • Particularly product specific source information

• Changes in use, new contaminants, supporting data

Environmental fate of contaminants

Methods and approaches for filling data gaps*

Methods and approaches for comparing chemicals with varying amounts of data*

12

About Me

Joined DTSC in August of 2014

Completed a PhD in Environmental Chemistry at Stony Brook University • Studied the occurrence, fate and transport of

quaternary ammonium compounds (QACs)

• Researched the use of QACs as sewage tracers

• Used QACs for source allocation of a number of aquatic contaminants

13

QAC Research and SCP Research Needs

Monitoring data (including California specific) • Aquatic environments, indoor environments,

sensitive subpopulations

Contaminant source information • Particularly product specific source information

• Changes in use, new contaminants, supporting data

Environmental fate of contaminants

Methods and approaches for filling data gaps

Methods and approaches for comparing chemicals with varying amounts of data

14

A CASE STUDY: QACs

- Evidence for use of QACs (DTDMAC 18:18) as a sewage tracer

- Examples of the type of research that helps fill the SCP research needs

15

Acknowledgements

Bruce Brownawell, Stony Brook University

Xiaolin Li, Xiamen University

EPA STAR

New York Department of State

16

Sewage Tracers

Source specific contaminants or properties that can be used to characterize the extent and distribution of sewage impacts in aquatic environments

Particle reactive sewage tracers specifically track the distribution of particles that have been affected by sewage

Examples include a contaminant like silver or stable isotope ratios of C and N in organic matter

17

Particle Reactive Sewage Tracers

Assist in understanding: • intensity of sewage impacts

• transport of sewage affected particles

• contaminant source allocation

• the biogeochemistry of other chemical contaminants

• sediment transport and deposition

18

Desired Qualities of Particle Reactive Sewage Tracers

sewage is the dominant source

extremely particle reactive

large environmental concentrations, high sensitivity, low background levels

known time history

persistent in the environment being studied

19

Previously Used Sewage Tracers

Ag, LABs, fecal sterols

variable time histories and persistence reported

TAMs (trialkylamines, impurities in QACs)

20

TAMs

QACs as Sewage Tracers

Li and Brownawell measured high levels of QACs in U.S coastal waters

Proposed their use as stable, particle reactive sewage tracers

21

Quaternary Ammonium Compounds

- Permanently charged cations

- High production volume chemicals

- Uses:

- Personal care products

- Conditioners

- Disinfectants/anti-microbials

- Softeners/anti-statics

22

QACs

23

DADMAC : n=8,10

DTDMAC: n=12–18 ditallow dimethyl

alkyltrimethyl ammonium compounds

benzylalkyl dimethyl ammonium compounds

dialkyl dimethyl ammonium compounds

- Positive charge and hydrophobicity associated with the carbon side chains results in extremely particle reactive compounds

QAC Sediment Extraction method

0.10 g of freeze dried sediment

3 x 10mL extractions with acidic methanol in a heated sonication bath

Two part cleanup step: • LLE with chloroform

• Anionic exchange resin

HPLC-ToF-MS for analysis • Two dilutions needed

Li and Brownawell 2010, Lara-Martin et al 2010 24

QACs as Sewage Tracers

25

sewage is the dominant source

extremely particle reactive

large environmental concentrations, high sensitivity, low background levels

known, steady time history

persistent in the environment being studied

✔

✔

✔

26

QACs as Sewage Tracers

large environmental concentrations, high sensitivity, low background levels

known, steady time history

persistent in the environment being studied

✔

QACs: Previous Work

• A majority of sediment studies in the US done by Li and Brownawell

• Li and Brownawell (ES&T,2010)

27

88

Figure 3.1. Surface sediment sample locations in the NY/NJ Harbor Complex. Blue

squares indicates samples collected from Flushing Bay; red triangle indicates

samples collected near CSO outlets or CSO impacted Passaic River; black dots

indicate locations of all other sample collection sites.

Concentrations of QAC homologues and other organic

contaminants in 1998 NY/NJ REMAP Sediments (n=45)

TOC

(%)

PAH

(mg/g)

PCB

(mg/g )

NPEO

(mg/g)

QACs

(mg/g)

Minimum 0.19 n.d. n.d. 0.030 0.98

Maximum 10 91 2.5 78 110

Mean 3.6 5.8 0.15 6.1 34

Median 3.0 2.3 0.043 2.4 27

Study Site 1: Hempstead Bay, NY

28

Hempstead Bay Sample Sites

29

Sewage Treatment Plant

Flow

Bay Park STP 50 MGD

Long Beach STP 5 MGD

Lawrence STP 1.3 MGD

West Long Beach STP

0.6 MGD

QACs in Hempstead Bay

30

0

20,000

40,000

60,000

80,000

100,000

120,000

0 5 10 15 20 25

ΣQ

AC

s n

g/g

km from the BPO

QACs in Hempstead Bay

31

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

0 5 10 15 20 25

DT

DM

AC

18

:18

ng

/g

km from the BPO

DTDMAC 18:18 represents 40-60% of ƩQACs found in the samples.

Study Site 2: Long Island Sound

32

Long Island Sound Sample Sites

33

61

Figure 2.1. a) Locations of sediment grab samples taken in 2008 in Long Island Sound, NY and b)

sample locations from the East River and WLIS. Yellow dots represent stations from the 2008 transect,

orange dots represent samples from Li, 2009, and red dots represent sewage outfalls.

a)

b)

Long Island Sound

34

0

2000

4000

6000

8000

10000

12000

14000

16000

0 10 20 30 40 50 60 70 80

ƩQ

AC

s n

g/g

km from Tallman Island STP outfall

Long Island Sound

35

0

1000

2000

3000

4000

5000

6000

7000

0 10 20 30 40 50 60 70 80

DT

DM

AC

18

:18

ng

/g

km from Tallman Island STP outfall

DTDMAC 18:18 represents 40-50% of the ƩQACs found in the samples.

Triclosan vs. BACs

36 Pulse of the Bay, 2013, SFEI

0

50

100

150

200

250

300

350

400

450

500

0 10 20 30 40 50 60 70 80

ƩB

AC

s n

g/g

km from Tallman Island STP outfall

ƩBACs in Long Island Sound

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

0 5 10 15 20 25

ΣB

AC

s n

g/g

km from the BPO

ƩBACs in Hempstead Bay

QAC Research and SCP Research Needs

Monitoring data (including California specific) • Aquatic environments, indoor environments,

sensitive subpopulations

Contaminant source information • Particularly product specific source information

• Changes in use, new contaminants, supporting data

Environmental fate of contaminants

Methods and approaches for filling data gaps

Methods and approaches for comparing chemicals with varying amounts of data

37

QACs as Sewage Tracers

38

sewage is the dominant source

extremely particle reactive

large environmental concentrations, high sensitivity, low background levels

known time history

persistent in the environment being studied

What the literature says: lab studies

Lab biodegradation estimates suggest that QACs can be readily degraded under oxic conditions

Anoxic lab studies suggest much reduced biodegradation

Biodegradability ↓ as chain length ↑

Lab studies do not always = real world environment

39

QAC mass balances in sewage treatment plants

40

Clara et al., 2007

- Trialkyl methyl ammonium chloride - Dominant source to environment is thought to be as impurities in

QACs; similar time histories - decreases in the ratio of DTDMAC 18:18 to TAMAC 16:18:18 with

distance from the source would indicate preferential degradation or desorption of DTDMAC 18:18

Persistence: Comparison to TAMAC 16:18:18

41

0

50

100

150

200

0 5 10 15 20

km from Bay Park STP outfall

DTDMAC 18:18/TAMAC 16:18:18 in

HB

Sediment Cores

A way to understand the changes in environmental inputs of contaminants over time (decades)

Sediment cores from anoxic, depositional environments can preserve important information about historical inputs

42

43 1930

1940

1950

1960

1970

1980

1990

2000

2010

0 20 40 60

HB Core 3

DTDMAC 18:18/TAMAC

16:18:18

1970

1975

1980

1985

1990

1995

2000

2005

2010

0 50 100

HB Core 11

DTDMAC 18:18/TAMAC

16:18:18

- decreases in the ratio of DTDMAC 18:18 to TAMAC 16:18:18 with depth in a core would indicate degradation of DTDMAC 18:18

Persistence: Comparison to other chemicals

Additional data for persistence

Matched cores over 20 years indicating no in situ degradation

Degradation experiments using Hempstead Bay sediment indicate no degradation for all but smallest QACs • Oxic and anoxic

44

QAC Research and SCP Research Needs

Monitoring data (including California specific) • Aquatic environments, indoor environments,

sensitive subpopulations

Contaminant source information • Particularly product specific source information

• Changes in use, new contaminants, supporting data

Environmental fate of contaminants

Methods and approaches for filling data gaps

Methods and approaches for comparing chemicals with varying amounts of data

45

QACs as Sewage Tracers

46

known time history

persistent in the environment being studied

DTDMAC 18:18 time history

First uses as fabric softeners in the mid to late 1950’s

Production peaked in the late 1980’s due to a 1991 voluntary phase out in Europe

• 2-8 mg/g DTDMACs found in sewage sludge

47

US International Trade Commission Data (ended in 1993)

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

1960 1970 1980 1990 2000

DT

DM

AC

pro

du

ctio

n

(1000's

of

pou

nd

s)

year

DTDMAC 18:18 time history: Sediment Cores

A way to understand the changes in environmental inputs of contaminants over time (decades)

Sediment cores from anoxic, depositional environments can preserve important information about historical inputs

Now know that at least the biggest QACs are extremely persistent in anoxic, deposition environments

48

Cores Sampled – Hempstead Bay

49

50

Cores Sampled – Jamaica Bay

DTDMAC 18:18

51

0 20,000 40,000 60,000 80,000 100,000

JB Core 7

Hempstead Bay, NY Jamaica Bay, NY

0 5,000 10,000 15,000 20,000 25,000 30,000

HB Core 11

1935

1940

1945

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

0 50,000 100,000 150,000 200,000

HB Core 3

ng/g

1 cm/yr 2.55 cm/yr .75 cm/yr

ATMAC 20-22

52

1935

1940

1945

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

0 2,000 4,000

HB Core 3

0 50 100 150

HB Core 11

0 2,000 4,000

JB Core 4

0 500 1,000

JB Core 7

Lara-Martin et al. (2010) noted 3 to 4 year doubling times

ng/g

QAC Research and SCP Research Needs

Monitoring data (including California specific) • Aquatic environments, indoor environments,

sensitive subpopulations

Contaminant source information • Particularly product specific source information

• Changes in use, new contaminants, supporting data

Environmental fate of contaminants

Methods and approaches for filling data gaps

Methods and approaches for comparing chemicals with varying amounts of data

53

APPLICATION OF QACS AS SEWAGE TRACERS

1. Source history of individual QACs to the environment

2. PBDE sources in NY/NJ Harbor

3. Source and fate of DEHP in Hempstead Bay

4. Source of trace metals to an Hempstead Bay

54

1. Source history of individual QACs

DTDMAC 18:18 • most hydrophobic, particle reactive, resistant to

degradation, relatively constant time history over last 20 years

• can compare to other QACs that may undergo degradation during burial

• changes in the ratio of an individual QAC to DTDMAC 18:18 can indicate degradation or differences in use histories of other QACs

Li (2009) hypothesized continued increase in the use of small DTDMACs/DADMACs/BACs

55

56

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

0 0.1 0.2 0.3 0.4

BAC 18

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

0 0.5 1 1.5 2

DTDMAC 16:18

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

0 0.05 0.1 0.15

DTDMAC 14:16

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

0 0.2 0.4 0.6

DTDMAC 16:16

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

0 0.01 0.02 0.03

DADMAC 10:10

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

0 0.01 0.02 0.03 0.04

BAC 14

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

0 0.01 0.02 0.03 0.04

DTDMAC 12:14

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

0 0.02 0.04 0.06

DTDMAC 14:14

= JB Core 4 = JB Core 7 = HB Core 3

Benedict, L. A., 2007 PhD

thesis; RPI

Percentage of ∑tri-hexaBDE in PBDEs in sediments from Hudson River Basin

∑tri-hexaBDE% <5%

5%< ∑tri-hexaBDE% <9.8%

∑tri-hexaBDE% >12%

Industrial sources

STP sources

2. PBDEs in NY/NJ Harbor

PBDEs and QACs in NY/NJ Harbor

Li 2009, PhD Thesis

3. Di-ethylhexl phthalate (DEHP)

- Plasticizer

- Suspected endocrine disruptor

- Sewage has been suggested as an important source to aquatic environment but no empirical evidence for this - Other potential sources include landfills, runoff, atmospheric

deposition

- Listed in many of the SCP Product Categories

DEHP in Hempstead Bay

60

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0 2 4 6 8 10 12 14 16 18 20

DE

HP

ng/g

km from Bay Park Outfall

Probable effects level for DEHP in sediments (MacDonald et al. and 1996)

DEHP and DTDMAC 18:18 in Hempstead Bay

61

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0 5000 10000 15000 20000 25000 30000 35000 40000

DE

HP

ng

/g

DTDMAC 18:18 ng/g

R2=0.94

DEHP/DTDMAC 18:18 in HB

62

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 5 10 15 20

DE

HP

/DT

DM

AC

18

:18

km from Bay Park Outfall

0.000

0.002

0.004

0.006

0.008

0.010

0.012

0.014

0 5000 10000 15000 20000 25000

Zn

/Fe

63

0.00000

0.00001

0.00002

0.00003

0.00004

0.00005

0.00006

0.00007

0 5000 10000 15000 20000 25000

Ag/F

e

0.000

0.001

0.002

0.003

0.004

0.005

0.006

0.007

0 5000 10000 15000 20000 25000

Cu

/Fe

0.000

0.001

0.002

0.003

0.004

0.005

0.006

0.007

0 5000 10000 15000 20000 25000

Pb

/Fe

DTDMAC 18:18 (ng/g)

Fe > 2.25%

4. Particle Reactive Metals in Hempstead Bay

QAC Research and SCP Research Needs

Monitoring data (including California specific) • Aquatic environments, indoor environments,

sensitive subpopulations

Contaminant source information • Particularly product specific source information

• Changes in use, new contaminants, supporting data

Environmental fate of contaminants

Methods and approaches for filling data gaps

Methods and approaches for comparing chemicals with varying amounts of data

64

Conclusions

DTDMAC 18:18 potential as a sewage tracer

Illustrate the type of environmental research critical to SCP program • Help assess the chemicals most likely potential for

adverse impacts from environmental exposures

• Help in fulfilling Policy Priorities from Work Plan

65

Thank you anne.doherty@dtsc.ca.gov

http://www.dtsc.ca.gov/SCP

66