2006 Progress Report: Exposure Assessment and Intervention Project (EAIP)

EPA Grant Number: R829391C004
Subproject: this is subproject number 004 , established and managed by the Center Director under grant R829391
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: CECEHDPR - University of Medicine and Dentistry of New Jersey Center for Childhood Neurotoxicology and Assessment
Center Director: Lambert, George H.
Title: Exposure Assessment and Intervention Project (EAIP)
Investigators: Lioy, Paul J. , Georgopoulos, Panos G. , Shalat, Stuart L. , Weisel, Clifford P.
Institution: University of Medicine and Dentistry of New Jersey , University of Medicine and Dentistry of New Jersey
EPA Project Officer: Fields, Nigel
Project Period: November 1, 2001 through October 31, 2006
Project Period Covered by this Report: November 1, 2005 through October 31, 2006
RFA: Centers for Children's Environmental Health and Disease Prevention Research (2001) RFA Text |  Recipients Lists
Research Category: Children's Health , Health Effects , Health

Objective:

The research being conducted within the Exposure Assessment and Intervention Project (EAIP) is continuing to address specific objectives associated with our first hypothesis: the unique behaviors of neurologically impaired children lead to higher exposures from single and multiple neurotoxicants in their personal or residential environment. The specific objectives of this research project are to: (1) implement a phased, community-based field study on neurotoxicant exposures and intervention strategies among community groups with families who have children identified with neurological disorders or deficits or diagnosed with the early indicators of such diseases; (2) document the exposure pathways that can lead to contact with neurotoxicants by the affected children using questionnaires and geographical information system (GIS) mapping (each will be used to qualitatively identify personal pathways or environmental sources, respectively); (3) implement an exposure measurement program based on the preceding analyses to establish the levels of specific neurotoxicants in the residence or personal environment of children at risk to neurological disorders or deficits; and (4) complete a detailed video assessment of the routine activities of these children and link directly with clinically based neurobehavioral assessments of children.

Progress Summary:

The team of investigators who comprise the membership of the EAIP have been administering questionnaires and carrying out the videography on the children enrolled in the study with autistic spectrum disorder (ASD). The children are video-recorded continuously on a single day for approximately 4 hours with the exception of the time the children are in the bathroom or when parents request privacy. The study video protocol continues to utilize a Hitachi DZMZ580A mini-DVD camcorder. This device records directly on a mini-DVD (1.4gb) and allows videos to be played back directly on computers and eliminates the computer intensive activity of videotape conversion to DVD media. This approach decreased the computer time necessary to evaluate videos by approximately 50 percent and brought with it a significant technical improvement in video quality as well. All mini-DVDs are copied onto a standard DVD for archiving and data protection purposes.

The DVDs from the cameras are loaded directly onto an Apple G4 computer for analysis. The VTD (Virtual Timing Device) software (SamaSama Consulting) and the DVD are simultaneously run on the computer. The software is a refinement of the VideoTraq software described by Zartarian, et al. (1997a) and used previously in children’s mouthing and food handling activity studies (Zartarian, et al., 1997b, 1998; Freeman, et al., 2001a,b; Akland, et al., 2000; Black, et al., 2004). It provides both frequency and duration of activities. The template that is employed was developed based on the experience of the review of more than 400 hours of recordings during the previous studies. It allows for the recording of all activities of interest. The location grid is used to track indoor and outdoor behaviors. The activity grid reflects both the child’s contact with water (i.e., use of wading pools or tubs during taping) and the child’s contact with the floor. Both hand-to-mouth and object-to-mouth contacts including superficial contact with the lips as well as insertion in the mouth are recorded. Dietary (food utensil, cup and bottle) and pacifier contact with the mouth is not considered object-to-mouth contact. Food handling also is quantified. Each video is reviewed twice, first transcribing the right-hand contacts and then the left-hand contacts. When both hands are holding an object to mouth, the activity is only recorded as mouthing with the right hand.

At the present time, a total of 47 children have been video-recorded (41 boys, 6 girls), with a mean age of 33 months (range 25-42 months). Video analysis was completed on a total of 40 children as of May 17, 2005. . A preliminary statistical analysis was carried out on the first 40 children utilizing SPSSTM version 13.0. An additional comparison was carried out between ASD children and those observed for a previously conducted study (Shalat, et al., 2003; Black, et al., 2004) and those in the current study. Both duration and frequency of mouthing behaviors were compared. Although the median values were lower among the ASD children for both hand-to-mouth and object-to-mouth activity, a comparison of the distributions (Tables 1 and 2) show higher values among the ASD children at the upper ranges of the distribution. The lower levels of median object-to-mouth activity in the ASD children, however, may be explained by a far higher prevalence of the use of pacifiers in this population, in conjunction with the fact that pacifier use was not scored in either study. A manuscript on the current study was submitted this year and is under final revision after peer review (Black, et al., 2005).

Table 1. Mouthing Frequency (Median Contacts Per Hour)


Percentile

Hand-To-Mouth

Object-To-Mouth

Study

ASD1

RBHCP2

ASD1

RBHCP2

25

4.5

4.9

1.0

3.1

50

8.6

11.2

3.3

5.7

75

17.8

16.1

8.1

11.8

90

37.5

31.8

16.7

22.7

Maximum

44.9

34.7

86.5

24.1

Table 2. Mouthing Duration (Median Percent of Recorded Time)


Percentile

Hand-To-Mouth

Object-To-Mouth

Study

ASD1

RBHCP2

ASD1

RBHCP2

25

0.3

0.4

0.1

0.4

50

1.0

1.4

0.4

0.8

75

3.1

2.1

2.4

1.9

90

7.0

3.9

5.7

3.9

Maximum

32.0

5.2

15.2

4.6

1ASD=Autism Spectrum Disorder (n=40)
2RBHCP=Rio Bravo Healthy Child Project (n=18)

Microenvironmental and Biomarker Measurements

Sampling Scheme. The samples collected included: dust by wipe and vacuum sampling for trace elemental and pesticide analyses, first morning tap water samples for metals and volatile organic compounds (VOCs) analyses, air samples for VOCs analyses, urine for metal and pesticide metabolites analyses, blood for lead and VOCs analyses, and hair for lead and mercury analyses. The measured concentrations were compared to health-based standards or levels commonly measured in homes in the United States, particularly in New Jersey, to determine if the concentrations in these homes are elevated compared to the norm and when the results were reported to the participants to facilitate their understanding of the findings. The comparisons used were: (1) for water, the New Jersey Department of Health (NJDOH) and the U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL); (2) for air, the New Jersey Levels in Urban Centers; (3) for blood, the Centers for Disease Control and Prevention (CDC) reference ranges; (4) for floor dust, the New Jersey Residential Levels or New Jersey Department of Environmental Protection (NJDEP) Soil Cleanup Lead Floor Standard; and (5) for hair and urine, the National Health and Nutrition Examination Survey results.

At the time of this report microenvironmental samples have been collected and analyzed from 42 homes. In general the contaminant levels have been lower than or similar to other values that have been measured in other New Jersey studies, which are predominantly from urban sites, and from the National Human Exposure Assessment Survey, which was a population-based sampling of homes in EPA Region 5 (Midwest). Water VOC concentrations all have been below the standards (and below detection for the vast majority of samples), with the exception of several water samples, which contained elevated levels of trihalomethanes (THMs). Because the THM standard is based on the average of four measurements during a year, a single high reading does not violate the standard. For those samples where that exceeded the composite THM standard, the water company was contacted to determine if there was a problem with their system and a second water sample was obtained. In each case the second sample found THM levels that were lower than the composite THM standard.

Although individual homes had VOC air concentrations that exceeded 95 percent of VOC concentrations measured elsewhere in New Jersey, the mean values across the homes were similar to previously reported values for homes in New Jersey, and none of the compounds mean concentrations exceeded the 95 percent associated with comparison homes. By definition, 1 in 20 homes is at the 95 percentile of a population, so individual higher values were expected. Because the distributions are similar, the results suggest that this population does not have excess exposures to each of the sampled agents, and that the indoor VOC air levels are consistent with concentrations measured elsewhere in New Jersey and in other locales. Statistical comparison will be done when all data are collected. Pesticides levels were detected only in a few homes (three for chlorpyrifos, one for diazinon, and six for malathion).

As reported last year, the mass dust loadings and the lead loadings have been low in most of the homes. This low dust loading (µg/ft2) probably is the result of the absence of large dust particles that usually are generated from indoor activities, which would have a large organic concentration. In contrast, the very low dust levels in individual homes appear to have the concentrated metals in the dust (µg/g) with the result of some metals having higher than NJDEP soil residential cleanup standards. This is attributed to the lack of large particles that do not contain metals. A single home had a lead loading on the floor exceeding the Federal Residential Standard for Lead Loading in house dust of 40 µg/ft2, and an intensive intervention was conducted in that house. The intervention included hiring a consulting firm to identify all sources of lead indoors using a portable X-ray fluorescence spectroscopy, and discussions by Dr. Lambert with the state and county to try to obtain financial aid for the family to do a thorough abatement. The intervention still is ongoing. The median values of metal concentrations for house dust in both the vacuum and wipe samples were below the Soil Cleanup Standard for all metals. The mean and median water metals concentrations were below the NJDOH or EPA MCL, though the copper concentrations found in two homes and lead concentrations found in one home were above the standards. Advice was provided to the participants on methods to decrease the concentrations.

The GIS analyses will be completed on the toxic release inventory compiled by the EAIP for the State of New Jersey through this past year. This will be done once the location of each home is determined and after the number of children who complete the sampling program reaches 50; this is expected to be started by the end of the summer.

Biological samples have been collected to evaluate the body burden of target contaminants in the children. Forty-one hair and blood samples and 24 urine samples have been collected. The children’s mercury concentration in hair was above the top 10 percent of the CDC reference range (400 ng/g) for 4 of the 41 samples measured (approximately 10%, consistent with general population) to date. None of the lead concentrations in hair exceeded the top 10 percent (100,000 ng/g) found nationally by the CDC and few exceeded the mean CDC reference standard (10,000 ng/g). Although no reference values are reported for manganese, levels consistently were lower than either mercury or lead. For the children with higher hair mercury concentrations, fish ingestion seems to be the probable source, and it was suggested to the participants that they reduce fish consumption. The low concentration of lead in the hair of children enrolled in the study, as compared to levels in the general population, is consistent with the low dust loading in the homes, which reduced exposure from that exposure pathway. The blood lead concentrations never exceeded the 10 µg/dL CDC guidance level. Urinary metal levels also were within the range reported in national surveys. Only a single subject had measurable levels of urinary pesticide metabolites (chlorpyrifos). Blood VOC levels typically were below detection, with no compound having measurable levels in more than six samples. The compounds that were above detection mostly were associated with automobile emissions (aromatic compounds), chlorinated drinking water (THMs), air freshener (1,4-dichlorobenzene), and dry cleaned clothes (tetrachloroethylene).

For individual homes where a pollutant in a microenvironmental sample was higher than the comparison value, potential sources of the pollutant were considered based on the questionnaire data and the observations made by the sampling team. Subsequently the EAIP Team sent a letter with suggested interventions that could be followed to reduce the concentrations and potential exposures. Samples were collected in four homes in which the participants have followed the interventions suggested by the team. Declines in the levels of the pollutants of concern were evident in each case.

Future Activities:

No single exposure has been found to be consistently high, and the dust levels have been consistently lower than in previous studies of the general population. We plan to: (1) continue to collect and analyze samples as homes are recruited, and (2) continue to follow up with intervention strategies as warranted. When the health data on regression within the children being studied by Dr. Lambert and colleagues in the health project become available statistical analyses between the exposures associated with those children that were shown to have regression will be compared to results obtained from children that did not show regression. This analysis is planned to be completed by the end of Year 4. At that time, Dr. Weisel will complete a manuscript on the analyses. Dr. Lioy recently completed a review article on the dynamics and chemistry of semivolatile compounds indoors. It was peer reviewed and under final revision.


Journal Articles on this Report : 1 Displayed | Download in RIS Format

Other subproject views: All 11 publications 7 publications in selected types All 7 journal articles
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Type Citation Sub Project Document Sources
Journal Article Lioy PJ. Employing dynamical and chemical processes for contaminant mixtures outdoors to the indoor environment: the implications for total human exposure analysis and prevention. Journal of Exposure Science & Environmental Epidemiology 2006;16(3):207-224. R829391 (2004)
R829391 (2005)
R829391 (2006)
R829391C004 (2006)
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  • Supplemental Keywords:

    children’s health, disease and cumulative effects, ecological risk assessment, environmental chemistry, health risk assessment, susceptibility, sensitive population, genetic susceptibility, toxicology, assessment of exposure, assessment technology, autism, behavioral assessment, behavioral deficits, childhood learning, developmental disorders, developmental effects, environmental health hazard, environmental toxicant, exposure assessment, gene-environment interaction, neurodevelopmental, neurological development, neuropathological damage, neurotoxic, neurotoxicity, outreach and education, public health,, RFA, Scientific Discipline, Health, Health Risk Assessment, Risk Assessments, Susceptibility/Sensitive Population/Genetic Susceptibility, Ecological Risk Assessment, Children's Health, genetic susceptability, Biology, childhood learning, neurotoxic, behavioral assessment, gene-environment interaction, developmental effects, children, neurotoxicity, assessment of exposure, public health, behavioral deficits, environmental health hazard, autism, outreach and education, assessment technology, developmental disorders, exposure assessment, neurological development

    Progress and Final Reports:

    Original Abstract
    2004 Progress Report
    2005 Progress Report


    Main Center Abstract and Reports:

    R829391    CECEHDPR - University of Medicine and Dentistry of New Jersey Center for Childhood Neurotoxicology and Assessment

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R829391C001 Neurotoxicant Effects on Cell Cycle Regulation of Neurogenesis
    R829391C002 Adhesion and Repulsion Molecules in Developmental Neurotoxic Injury
    R829391C003 Disruption of Ontogenic Development of Cognitive and Sensory Motor Skills
    R829391C004 Exposure Assessment and Intervention Project (EAIP)
    R829391C005 Clinical Sciences Project