Houston Exposure To Air Houston Exposure To Air Toxics Study - - PowerPoint PPT Presentation

Houston Exposure To Air Houston Exposure To Air Toxics Study (HEATS) Toxics Study (HEATS) January 2010 January 2010

Susana Hildebrand, P.E. Mike Aplin, M.S. Michael Honeycutt, Ph.D. Lindsey Jones, M.S.

2

Background

3

HEATS Investigators

• University of Texas Health Science Center at

Houston, School of Public Health

– Maria Morandi (Principal Investigator) – Tom Stock, Ron Harrist, Jaymin Kwon

• University of Texas Medical Branch (UTMB)

– Sharron Petronella

• RTI International, RTP, NC

– Roy Whitmore – Michael Phillips

4

Funding and Management

• US Environmental Protection Agency ($400K)
• Texas Commission on Environmental Quality ($477K)
• Mickey Leland NUATRC ($250K)
• Texas Environmental Research Consortium ($50K)
• East Harris County Manufacturers Association ($50K)

Total Project = $1,252,000

• Other non-funding participants (Harris County & City of Houston)

5

Main Objective

• Determine if personal exposure to a

group of selected hazardous air pollutants (HAPs) for residents in the Ship Channel (SC) area of Houston (high density of point source emissions of HAPs) are higher than for residents of the Aldine area of Houston (few point source emissions of HAPs).

6

Methods

7

HEATS Study Areas

Ship Channel Area Aldine Area

8

Fugitive and Point Source Emissions of Selected HAPs from Toxic Release Inventory (TRI) in Each Area (2003 data in pounds/year)

HAPs Total SC (Table 2a) Total Aldine (Table 2b) 1,3-Butadiene 149,973 Benzene 113,126 227 Ethylbenzene 38,932 79 m-Xylene 28,271 MTBE 76,462 6,420 n-Hexane 174,200 764 Naphthalene 4,255 p-,o-Xylene 52,043 44,120 Styrene 307,628 143,400 Tolune 133,926 676 Xylenes (Mixed) 164,843 306 Total 1,245,328 195,992

9

Participants

• Random sample of adults in each area.
• The reference area (Aldine) was selected to

have socio-demographically similar characteristics to the SC area.

• Only non-smoking households were included.

Ship Channel Area 40 Adults; 14 Children Aldine Area 38 Adults; 21 Children

10

Select VOCs Were Measured

• Fixed site concentrations

– Ambient concentrations at TCEQ monitoring location closest to each home (weighted average)

• Outdoor residential concentrations
• Indoor residential concentrations
• Personal concentrations

11

Measurements & Information

• Perkin Elmer (PE) tube and organic vapor

monitor (OVM) passive sampling devices

• Ambient data from PE tubes co-located at

the TCEQ monitoring site closest to each home samples (weighted average)

• Air exchange rates for houses
• Survey of participant characteristics
• Time location budgets and personal activities
• Questionnaire on health symptom patterns
• Questionnaire on environmental risk

perception

12

General Approach

• Day 1 – Explain study, written consent to

participate, baseline questionnaire, walkthrough survey, placement of tracer sources, GPS

• Day 2 – Place VOC, temp/humid devices

(outdoor, indoor, personal), instructions on handling, time-activity logs

• Day 3 – Retrieve all samplers, review time-

activity logs, household activity questionnaire, study incentive provided

• Day 4 – UTMB administers health symptom

and risk perception questionnaires

13

Discussion

• f

Study Challenges

14

Difficulties With Enrollment and Retention of Participants

• Recruitment and retention proved far more

difficult than anticipated & was a major barrier to timely progress of study

• Hurricane Ike forced some to leave their

homes and caused extended power outages

• General disinterest in participating in both

areas

• Cultural and gender differences in both areas
• Smoking households

15

Actions Taken to Improve Recruitment

• Informational mail-outs
• Direct placement of brochures
• Radio and cinema announcements
• Public Service announcement by Senator

Gallegos

http://www.sph.uth.tmc.edu/mleland/Webpages/HEATS.htm

• Meetings with local reps and community
• rganizers
• RTI tried to locate super recruiters
• Incentive raised from $50 gift cards to $100

cash

16

Difficulties with PE Tubes

• Detroit Exposure and Aerosol Research

Study (DEARS), successfully used PE Tubes

• NUATRC SAP, TCEQ and EPA pushed for

UTSPH to use PE tubes, not OVM, which cannot measure 1,3-butadiene

• There was also a consensus that the PE

tubes could obtain lower detection limits compared to the OVM (as seen in DEARS)

• Early pilot study to compare results from two

methods and test out surveys and questionnaires

17

Differences between Alion and UTSPH and Other Difficulties with PE Tubes

• Blank contamination
• Spiking protocols for preparation of

standards and positive controls (Alion exposed blank tubes in controlled test atmospheres in a dynamic chamber, while UTSPH used flash injection of mixed standards in methanol)

• The GC/MS systems at each lab were

different

• Water management problems (interference)

for early eluting compounds

18

Target HAPs for PE Tubes

• Optimal VOCs

– Tetrachloroethylene – Ethylbenzene – m&p Xylene – o-Xylene – Styrene – 1,3,5-Trimethylbenzene – 1,2,4-Trimethylbenzene – 1,2,3-Trimethylbenzene – p-Dichlorobenzene

• Non-Optimal VOCs

– 1,3-Butadiene – Carbon Tetrachloride – Trichloroethylene – Benzene – Toluene

19

Hypotheses and Conclusions

20

Primary Hypothesis

• Personal exposures (personal air

concentrations) to TRI-reported target HAPs will be similar for both communities.

– Yes, there were no statistically significant differences in personal exposures for any of the

• ptimal VOCs measured

– Results were confirmed with a multivariate model including influential covariates

21

Mean Target VOC Concentrations in Adult Personal Samplers in Aldine and the Ship Channel

Analyte

1,3,5-Trimethylbenzene 1,2,4-Trimethylbenzene 1,2,3-Trimethylbenzene Tetrachloroethylene Ethylbenzene

• -Xylene

m&p-Xylene Styrene p-Dichlorobenzene

Air Concentration (ug/m3)

5 10 30 35 40 Aldine (n = 70) Ship Channel (n = 70)

Personal Adult

22

Mean Target VOC Concentrations in Child Personal Samplers in Aldine and the Ship Channel

Analyte

1,3,5-Trimethylbenzene 1,2,4-Trimethylbenzene 1,2,3-Trimethylbenzene Tetrachloroethylene Ethylbenzene

• -Xylene

m&p-Xylene Styrene p-Dichlorobenzene

Air Concentration (ug/m3)

10 20 50 60 70 Aldine (n = 34) Ship Channel (n = 19)

Personal Child

23

Secondary Hypothesis 1

• Fixed-site ambient concentrations will

be the same for both communities.

– Yes, for six of the optimal VOCs – Ambient concentrations based on the PE tube measurements for styrene, ethylbenzene, and 1,2,4-TMB were higher in the SC area

24

Mean Target VOC Concentrations at Fixed Site Monitoring Locations

Analyte

1,3,5-Trimethylbenzene 1,2,4-Trimethylbenzene 1,2,3-Trimethylbenzene Tetrachloroethylene Ethylbenzene

• -Xylene

m&p-Xylene Styrene p-Dichlorobenzene

Air Concentration (ug/m3)

0.0 0.5 1.0 1.5 2.0 2.5 Aldine (n = 68) Ship Channel (n = 72)

Fixed Site * * *

* Significantly Different

25

Secondary Hypothesis 2

• Residential outdoor concentrations will

be the same for both communities.

– Yes, there were no statistically significant differences in residential outdoor concentrations for any of the optimal VOCs measured

26

Mean Target VOC Concentrations at Residential Outdoor Monitoring Locations

Analyte 1,3,5-Trimethylbenzene 1,2,4-Trimethylbenzene 1,2,3-Trimethylbenzene Tetrachloroethylene Ethylbenzene

• -Xylene

m&p-Xylene Styrene p-Dichlorobenzene

Air Concentration (ug/m3)

1 2 6 7 Aldine (n = 70) Ship Channel (n = 70)

Residential Residential Ou Outdoor tdoor

27

Secondary Hypothesis 3

• Residential indoor concentrations will

be the same for both communities.

– Yes, for eight of the optimal VOCs – Styrene concentrations were higher in the Aldine area.

28

Mean Target VOC Concentrations at Residential Indoor Monitoring Locations

Analyte

1,3,5-Trimethylbenzene 1,2,4-Trimethylbenzene 1,2,3-Trimethylbenzene Tetrachloroethylene Ethylbenzene

• -Xylene

m&p-Xylene Styrene p-Dichlorobenzene

Air Concentration (ug/m3)

5 10 35 40 Aldine (n = 70) Ship Channel (n = 69)

Re Resi sident ntial ial Indoor Indoor *

* Significantly Different

29

Secondary Hypothesis 4

• Fixed-site concentration measurements

are good predictors of community (residential outdoor) concentrations for each area.

30

Fixed-Site Good Predictor of Residential Outdoor?

Aldine Ship Channel 1,3,5-Trimethylbenzene No No 1,2,4-Trimethylbenzene Yes Yes 1,2,3-Trimethylbenzene No No Tetrachloroethylene (PCE) No Yes Ethylbenzene Yes Yes

• -Xylene

Yes Yes m&p Xylene Yes Yes Styrene Yes No p-Dichlorobenzene Yes No

31

Secondary Hypothesis 5

• Fixed-site concentration measurements

are good predictors of indoor concentrations for each area.

32

Fixed-Site Good Predictor of Residential Indoor?

Aldine Ship Channel 1,3,5-Trimethylbenzene No No 1,2,4-Trimethylbenzene No Yes 1,2,3-Trimethylbenzene No No Tetrachloroethylene (PCE) Yes No Ethylbenzene Yes Yes

• -Xylene

Yes Yes m&p Xylene Yes Yes Styrene Yes No p-Dichlorobenzene Yes Yes

33

Secondary Hypothesis 6

• Fixed site concentration measurements

are good predictors of personal concentrations for each area.

34

Fixed-Site Good Predictor of Personal?

Aldine Ship Channel 1,3,5-Trimethylbenzene No No 1,2,4-Trimethylbenzene No Yes 1,2,3-Trimethylbenzene No No Tetrachloroethylene (PCE) No Yes Ethylbenzene Yes No

• -Xylene

Yes No m&p Xylene Yes No Styrene No Yes p-Dichlorobenzene No Yes

35

Secondary Hypothesis 7

• The estimated relative contribution of
• utdoor concentrations of HAPs of
• utdoor origin (i.e., carbon

tetrachloride) to indoor concentrations will be similar in each area.

– Yes, the areas were similar in terms of

• utdoor contributions to indoor

concentrations, except for 1,4-DCB.

36

Exploratory Hypothesis 1

• The proportion of participants reporting

at least one health symptom will be the same in both communities.

– Few instances of statistically significant differences in a comparison of means by geographic area; however few cases/symptoms were reported, which affected the power to detect a difference

37

Patterns of Health Symptoms

• Asthma in the past or current asthma

were not different between the areas

• Skin disorders, like eczema, in children

were more prevalent in SC area

• Depression and anxiety were also more

prevalent in SC area, but did not reach statistical significance

• No difference in reproductive outcomes

38

Exploratory Hypothesis 2

• Perception of environmental health risks will

be the same in both communities.

– Yes, for most variables.

39

Patterns of Risk Perception

• SC residents more likely to use and trust TV

as source of information, and also more likely to feel that the city/county health department demonstrated major responsibility for public health

• More Aldine residents responded that they

felt they had very little control over their health risks (70%) than Ship Channel residents (30%)

40

Exploratory Hypothesis 3

• The patterns of different health

symptoms (those associated with specific organ system functions) reported by the participants will be the same in both communities.

– Yes, overall.

41

Overall Conclusions

• Personal exposures were higher than residential

indoor or outdoor concentrations in both areas, which is entirely consistent with earlier studies.

• Ambient fixed-site measurements for some VOCs

(ethylbenzene, styrene, trimethylbenzenes) were higher in the SC area than in Aldine.

• Although there were some differences identified in

personal exposure related to participant characteristics like work status, or residential air exchange rates, including these variables did not alter the results of the hypothesis testing.

42

Figure 6. Average Tetrachloroethylene Concentrations and Standard Deviation at Different Monitoring Locations in the Study Areas

Monitoring Type

F i x e d S i t e R e s i d e n t i a l O u t d

• r

R e s i d e n t i a l I n d

• r

P e r s

• n

a l A d u l t P e r s

• n

a l C h i l d

Air Concentration (ug/m3)

1 2 3 4 7 8 Aldine Ship Channel

Tetrachloroethylene (PCE)

Exposure Duration Screening Level (ug/m3) Effect Acute (1 hour) 5,200 Odor Chronic (1 year to lifetime) 26 Liver cell cancer in rodents Source: TCEQ, Final Development Support Document for Tetrachloroethylene (2008)

43

Figure 7. Average Ethyl Benzene Concentrations and Standard Deviation at Different Monitoring Locations in the Study Areas

Monitoring Type

F i x e d S i t e R e s i d e n t i a l O u t d

• r

R e s i d e n t i a l I n d

• r

P e r s

• n

a l A d u l t P e r s

• n

a l C h i l d

Air Concentration (ug/m3)

2 4 6 8 10 12 Aldine Ship Channel

E t h y l B e n z e n e

Exposure Duration Screening Level (ug/m3) Effect Acute (1 hour) 2,000 Odor Chronic (1 year to lifetime) 200 Odor Source: TCEQ, Interim Effects Screening Level (currently under review); Based on Ontario Air Ministry (1988).

44

Figure 8. Average m- and p-Xylene Concentrations and Standard Deviation at Different Monitoring Locations in the Study Areas

Monitoring Type

F i x e d S i t e R e s i d e n t i a l O u t d

• r

R e s i d e n t i a l I n d

• r

P e r s

• n

a l A d u l t P e r s

• n

a l C h i l d

Air Concentration (ug/m3)

5 10 20 25 30 35 Aldine Ship Channel

m- and p-Xylene

Exposure Duration Screening Level (ug/m3) Effect Acute (1 hour) 350 Odor Chronic (1 year to lifetime) 610 Mild respiratory and neurologic effects in workers Source: TCEQ, Final Development Support Document for Xylenes (2009)

45

Figure 9. Average o-Xylene Concentrations and Standard Deviation at Different Monitoring Locations in the Study Areas

Monitoring Type

F i x e d S i t e R e s i d e n t i a l O u t d

• r

R e s i d e n t i a l I n d

• r

P e r s

• n

a l A d u l t P e r s

• n

a l C h i l d

Air Concentration (ug/m3)

2 4 8 10 12 Aldine Ship Channel

• X

y l e n e

Exposure Duration Screening Level (ug/m3) Effect Acute (1 hour) 350 Odor Chronic (1 year to lifetime) 610 Mild respiratory and neurologic effects in workers Source: TCEQ, Final Development Support Document for Xylenes (2009)

46

Figure 10. Average Styrene Concentrations and Standard Deviation at Different Monitoring Locations in the Study Areas

Monitoring Type

F i x e d S i t e R e s i d e n t i a l O u t d

• r

R e s i d e n t i a l I n d

• r

P e r s

• n

a l A d u l t P e r s

• n

a l C h i l d

Air Concentration (ug/m3)

2 4 6 8 Aldine Ship Channel

Styrene

Exposure Duration Screening Level (ug/m3) Effect Acute (1 hour) 110 Odor Chronic (1 year to lifetime) 470 Worker memory and sensory/motor function Source: TCEQ, Final Development Support Document for Styrene (2008)

47

Figure 11. Average 1,3,5-Trimethylbenzene Concentrations and Standard Deviation at Different Monitoring Locations in the Study Areas

Monitoring Type

Fixed Site Residential Outdoor Residential Indoor Personal Adult Personal Child

Air Concentration (ug/m3)

0.0 0.5 1.0 1.5 2.5 3.0 3.5 4.0 Aldine Ship Channel

1,3,5-Trimethylbenzene

Exposure Duration Screening Level (ug/m3) Effect Acute (1 hour) 1,250 Health-based Chronic (1 year to lifetime) 125 Health-based Source: TCEQ, Interim Effects Screening Level; Based on the NIOSH Recommended Standard, the TLV from American Conference of Governmental Industrial Hygienists, and the OSHA Standard

48

Figure 12. Average 1,2,4-Trimethylbenzene Concentrations and Standard Deviation at Different Monitoring Locations in the Study Areas

Monitoring Type

F i x e d S i t e R e s i d e n t i a l O u t d

• r

R e s i d e n t i a l I n d

• r

P e r s

• n

a l A d u l t P e r s

• n

a l C h i l d

Air Concentration (ug/m3)

2 4 6 8 10 12 Aldine Ship Channel

1,2,4-Trimethylbenzene

Exposure Duration Screening Level (ug/m3) Effect Acute (1 hour) 1,250 Health-based Chronic (1 year to lifetime) 125 Health-based Source: TCEQ, Interim Effects Screening Level; Based on the NIOSH Recommended Standard, the TLV from American Conference of Governmental Industrial Hygienists, and the OSHA Standard

49 Figure 13. Average 1,2,3-Trimethylbenzene Concentrations and Standard Deviation at Different Monitoring Locations in the Study Areas

Monitoring Type

F i x e d S i t e R e s i d e n t i a l O u t d

• r

R e s i d e n t i a l I n d

• r

P e r s

• n

a l A d u l t P e r s

• n

a l C h i l d

Air Concentration (ug/m3)

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Aldine Ship Channel

1 , 2 , 3

• T

r i m e t h y l b e n z e n e

Exposure Duration Screening Level (ug/m3) Effect Acute (1 hour) 1,250 Health-based Chronic (1 year to lifetime) 125 Health-based Source: TCEQ, Interim Effects Screening Level; Based on the NIOSH Recommended Standard, the TLV from American Conference of Governmental Industrial Hygienists, and the OSHA Standard

50

Figure 14. Average p-Dichlorobenzene Concentrations and Standard Deviation at Different Monitoring Locations in the Study Areas

Monitoring Type

F i x e d S i t e R e s i d e n t i a l O u t d

• r

R e s i d e n t i a l I n d

• r

P e r s

• n

a l A d u l t P e r s

• n

a l C h i l d

Air Concentration (ug/m3)

50 100 150 200 250 Aldine Ship Channel

p

• D

i c h l

• r
• b

e n z e n e

Exposure Duration Screening Level (ug/m3) Effect Acute (1 hour) 720 Odor Chronic (1 year to lifetime) 110 Nasal lesions in female rats Source: TCEQ, Final Development Support Document for 1,4-Dichlorobenzene (2009)

51

Main HEATS Conclusion

Personal exposures in the two areas are similar and do not appear to reflect the differences in the type and density of point source emissions or the ambient concentrations as measured at fixed sites in each of the areas.

52

After the Final Report

“This report is based on a limited analysis

• f a very rich database. Therefore

additional insights may be derived in future analyses of the data by exposure researchers.” In other words, the final report is not the final word on HEATS