Skip directly to search Skip directly to A to Z list Skip directly to site content





Exposure to or contact with chemical contaminants drive the ATSDR public health assessment process. The release or disposal of chemical contaminants into the environment does not always result in exposure or contact; chemicals have the potential to cause adverse health effects only if people actually come into contact with them. People may be exposed to chemicals by breathing, eating, or drinking a substance containing the contaminant or by skin (dermal) contact with a substance containing the contaminant.

When people are exposed to chemicals, the exposure does not always result in adverse health effects. The type and severity of health effects that may occur in an individual from contact with contaminants depend on the toxicologic properties of the contaminants, how much of the contaminant to which the individual is exposed, how often and/or how long exposure is allowed to occur, the manner in which the contaminant enters or contacts the body (breathing, eating, drinking, or skin/eye contact), and the number of contaminants to which an individual is exposed (combinations of contaminants). Once exposure occurs, characteristics such as age, sex, nutritional status, genetics, life style, and health status of the exposed individual influence how the individual absorbs, distributes, metabolizes, and excretes the contaminant. These factors and characteristics influence whether exposure to a contaminant could or would result in adverse health effects.

To assess the potential health risks associated with contaminants at this site, we compared contaminant concentrations to health assessment comparison (HAC) values. HAC values are media-specific contaminant concentrations that are used to screen contaminants for further evaluation. Non-cancer HAC values are called environmental media evaluation guides (EMEGs) or reference dose media evaluation guides (RMEGs), and are respectively based on ATSDR's minimal risk levels (MRLs) or EPA's reference doses (RfDs). MRLs and RfDs are estimates of a daily human exposure to a contaminant that is unlikely to cause adverse non-cancer health effects. Cancer risk evaluation guides (CREGs) are based on EPA's chemical specific cancer slope factors and an estimated excess lifetime cancer risk of one-in-one-million persons exposed for a lifetime. We used standard assumptions to calculate appropriate HAC values [7].

In some instances, we compare contaminant concentrations in water to EPA's maximumcontaminant levels (MCLs). MCLs are chemical-specific maximum concentrations allowed inwater delivered to the users of a public water system; they are considered protective of publichealth over a lifetime (70 years) of exposure at an ingestion rate of two liters per day. MCLs maybe based on available technology and economic feasibility. Although MCLs only apply to publicwater supply systems, we often use them to help assess the public health implications ofcontaminants found in water from other sources.

While exceeding a HAC value does not necessarily mean that a contaminant represents a publichealth threat, it does suggest that the contaminant warrants further consideration. The publichealth significance of contaminants that exceed HAC values may be assessed by reviewing andintegrating relevant toxicological information with plausible exposure pathways and exposurescenarios. Estimated exposures may be compared to reported No Observable and LowestObservable Adverse Effects Levels (NOAELs and LOAELs) and to known effect levels inhumans, when available.

Environmental Contamination

Sediment, groundwater, surface water, and surface soil samples included in our evaluation of the Hart site were collected during TNRCC investigations (1993, 1995, and 1998) and EPA investigations (1994). In reviewing these data, we relied on the information provided in the referenced documents and assumed that adequate Quality Assurance and Quality Control measures were followed with regard to chain-of-custody, laboratory procedures, and data reporting. The data packages were reviewed and validated by EPA Region 6 according to the USEPA Contract Laboratory Protocol [2]. The conclusions in this public health assessment are valid only if the referenced information is valid and complete.

Some of the samples were collected from areas inside the boundaries of the Hart Creosotingfacility while others were collected from outside the site boundaries (e.g., sediment from BigWalnut Run Creek). For the purpose of the public health assessment the term "on site" refers toall areas within the 8.8 acre NPL site and the term "off site" refers to all areas outside of the site'sproperty boundaries. With the exception of the sediment samples collected by the TNRCC in1998, sampling data evaluated in this public health assessment were collected prior to EPA'sremoval and containment of contaminated soil and sediments from the Hart Creosoting site in1995.

Samples were analyzed for volatile organic compounds, semi-volatile organic compounds, pesticides, PCBs and inorganics [2]. The maximum detected concentrations for each contaminant found in the different environmental media are presented in Appendix C. ATSDR comparison values for each of the contaminants also are listed in the tables. Contaminant whose concentrations were below ATSDR's comparison values were excluded from further consideration.

Exposure Pathways

In this section we evaluated the possible pathways for exposure to contamination at the Hart site. We examined these possible exposure pathways to determine whether people in the community could be exposed to (or come into contact with) contaminants from the site. Exposure pathways consist of five elements: 1) a source of contamination; 2) transport through an environmental medium; 3) a point of exposure; 4) a plausible manner (route) for the contaminant to get into the body; and, 5) an identifiable receptor population. Exposure pathways can be complete, potential, or eliminated. For a person to be exposed to a contaminant, the exposure pathway must be complete. An exposure pathway is considered completed when all five elements in the pathway are present and exposure has occurred, is occurring, or will plausibly occur in the future. A potential pathway is missing at least one of the five elements but may possibly be complete in the future as more data become available or site conditions change. Eliminated pathways are missing one or more of the five elements and will never be complete. The exposure pathways considered in our evaluation of this site are summarized in Table 1.

Table 1.

Evaluation of Exposure Pathways Hart Creosoting Company Site, Jasper, Texas
Pathway Name Contaminants of Concern Source Transport Media Point of Exposure Route of Exposure Exposed Population Time Comments
Foodchain No data Site wood treatment operation; spills; wastewater discharge Fish Off site downstream of facility Ingestion People fishing Big Walnut Run Creek downstream of Hart Past
Indeterminate public health hazard because of a lack of fish sampling data. Some site contaminants found in the sediment (PAHs) are known to bioaccumulate in fish.
Sediment Creosote constituents Site operations associated with wood treatment; spills Sediment Off site downstream of site Incidental Ingestion
Dermal Contact
People wading or swimming in Big Walnut Run Creek Past
No apparent public health hazard due to low concentrations of contaminants and infrequent exposure.
Groundwater Creosote constituents: primarily PAHs Site operations associated with wood treatment; spills Groundwater None Identified None Identified None Identified Past
No public health hazard since contaminants have not migrated toward private or public water supply wells.
Surface Water Big Walnut Run Creek None detected Site operations Surface water Off site Incidental Ingestion
Dermal Contact
People wading or swimming in Big Walnut Run Creek Past
Since water obtained from the intermittent creek between the site and Big Walnut Run Creek did not contain measurable levels of site contaminants, we have concluded that surface water downstream of the site in Big Walnut Run Creek presents no public health hazard.
Surface Soil Pre-removal: Creosote constituents Site operations associated with wood treatment; spills Soil On site Incidental Ingestion
Dermal Contact
Past on-site workers*
Past In the past this was a potential pathway of exposure; since contaminated soils on the site have been contained, people cannot come into contact with contaminated soils. Surface soil is considered to pose no public health hazard at this time.
Air No data Site operations associated with wood treatment; spills Air On site Inhalation Past workers Past In the past air releases may have occurred during the wood treatment process at Hart; however, since air data were not available for TDH/ATSDR to review, we were not able to evaluate the public health significance of this pathway. Since the Hart site is no longer operating the air pathway poses no public health hazard.
*in the past (1992) 7 people worked at Hart [2].

Evaluation of Possible Foodchain Pathway

According to interviews conducted by TNRCC staff in May 1998, Big Walnut Run Creek is used for fishing [1]. TNRCC staff also observed a man fishing downstream of the Hart site in Big Walnut Run Creek downstream of the confluence of the intermittent creek with Big Walnut Run Creek (Figure 3). This man stated that he fishes there about five days a week. He reported consuming red perch, sand roller bass, channel catfish, and bream caught in this area. Other individuals reported fishing just south of the Hart site near the U.S. Highway 96 bridge over Big Walnut Run Creek [1].

Fish sampling data for the waterways around the Hart Creosoting site were not available for TDH/ATSDR to review; however, some of the site contaminants found in the sediment, such as the PAHs, are known to bioaccumulate in fish. Since fish sampling data were not available and people have been documented fishing downstream from the site, we classified consumption of fish from Big Walnut Run Creek as an indeterminate public health hazard.

Evaluation of Possible Sediment Exposure Pathways

TNRCC collected 16 sediment samples from the intermittent creek and Big Walnut Run Creek in 1993 (n=8) and 1998 (n=8) [1, 2]. In 1994, Roy F. Weston collected five samples from the intermittent creek [1]. These results are shown in Appendix C Tables 2, 3, and 4, respectively.

The maximum reported concentration of benzo(a)pyrene in milligrams per kilogram (1.28 mg/kg) was measured in a sample collected from Big Walnut Run Creek approximately 2,200 feet downstream of the junction of Big Walnut Run Creek and the intermittent creek. People who wade or swim in Big Walnut Run Creek downstream of Hart Creosoting could come in contact with contaminated sediment. Because the maximum concentrations found in the sediment were low and exposure would be infrequent, we do not consider dermal contact with sediment to be a significant route of exposure. Daily ingestion of sediment containing 1.28 mg/kg benzo(a)pyrene would result in no apparent increased lifetime risk for the development of cancer. Since it is likely that ingestion of the sediment would be infrequent and contaminant concentrations are low, we would not expect exposure to the sediment to result in adverse health effects. We would not expect this type of infrequent exposure to result in adverse health effects; therefore, we have determined that the contaminated sediments pose no apparent public health hazard.

Evaluation of Possible Groundwater Exposure Pathways

The Hart site is located over the outcrop of the Jasper Aquifer [2]. The Jasper Aquifer and its associated geologic formations, composed of varying proportions of gravel, sand, silt, and clay, range in thickness from 600 feet to approximately 1,000 feet [2]. The shallow and deeper parts of the Jasper Aquifer are considered to be connected. Groundwater is encountered within nine feet of ground surface beneath the Hart site; groundwater contamination has been found between nine and twelve feet below ground surface [2]. Some of the on-site monitoring wells and the on-site process water well are contaminated with creosote compounds at concentrations above ATSDR's HAC values (Appendix C; Table 5).

There are thirty-nine private wells and two public water supply wells within four miles of the Hart site all of which draw water from the Jasper Aquifer [3]. The private wells are used for drinking water and irrigation purposes. The public water supply wells are used by the city of Jasper as the source for drinking water. The nearest off-site water wells are approximately 0.5 and 1.0 miles south of the Hart site. Each of these wells serves two people [2]. The depth of these wells is not known. These wells were sampled by Weston during the ESI, and no volatile organic or semi-volatile organic compounds were detected [2]. There is documentation that there was a 150-foot deep on-site water well near the former wood processing and drip track area that was used for wood processing activities [2]; however, we could not determine the current disposition of this well or whether the well was ever plugged.

The two operating city of Jasper public water supply wells, which serve approximately 12,000 users,are approximately three miles north of Hart and are part of a blended system [2, 8]. These wells arecompleted in the Jasper Aquifer at depths of 764 and 802 feet below ground surface [8]. Thesedeep wells, which are upgradient of the site, were not sampled during the ESI due to their locationand depth of completion; however, the city of Jasper routinely analyzes water from these wells asrequired by the Safe Drinking Water Act. This sampling, which includes testing for semi-volatileorganic compounds, some of which are contaminants associated with this site, has thus far notindicated that site contaminants have reached these wells.

Since there is no evidence that either the private or public drinking water wells have been affected bysite contaminants and since the on-site water wells are not used for potable purposes, groundwatercontamination at the Hart site currently does not pose a public health hazard. Because theshallow and deeper parts of the Jasper Aquifer are connected, there is some concern thatcontaminants in the shallow groundwater could eventually work their way down to parts of theJasper Aquifer that are used for drinking water [2]. Theoretically, contaminants could migratetoward the private water wells that are downgradient from the site. Based on available information,we would anticipate the likelihood for the downgradient migration to pose a significant health threatto the people using those wells to be small.

Evaluation of Possible Surface Water Exposure Pathways

The Hart Creosoting site is in the 100-year floodplain [1]. Hart Creosoting is bordered on the westby an unnamed intermittent creek that received surface water runoff from the Hart site in the pastand may still receive seepage from the site. This unnamed creek joins the perennially flowing BigWalnut Run Creek approximately 1 miles south and downstream of the site. Big Walnut RunCreek runs southwest for approximately 24 miles where it joins the Neches River [1]. According tointerviews conducted by TNRCC staff in May 1998, Big Walnut Run Creek is used for swimming[1]. There are no drinking water intakes for surface water supplies within 15 miles downstream ofthe Hart site [1].

In February 1993 the TNRCC collected three surface water samples downstream and one surface water sample upstream of the Hart facility. Volatile organic compounds were not detected in any of the samples. Semi-volatile organic compounds were detected in the two samples collected at the intermittent creek behind Pond A (Figure 2a) but not in the sample collected further downstream of the site (B-1) (Appendix C; Table 6). The semi-volatile organic compounds detected include the polycyclic aromatic hydrocarbons: 2,4-dimethylphenol, fluoranthene, naphthalene, phenanthrene, and phenol. Of these, 2,4-dimethylphenol [22 micrograms per liter (g/L)] and napthalene(53 g/L) exceeded their respective HAC values; however, these values are based on ingesting one to two liters of water per day (an unlikely exposure situation for creek water). Surface water collected approximately of a mile downstream of the site did not contain any of the site contaminants.

In January 1995, two surface water samples were collected by the TNRCC from on-site drainage areas [9]. One of the samples was collected from the west side of the former process area. The other sample was collected on the west side of Pond A. Polycyclic aromatic hydrocarbons benzo(b)fluoranthene, benzo(a)anthracene, and chrysene exceeded the MCLG (maximum containment level goal) for drinking water (zero g/L); no other HAC values were exceeded (Appendix C; Table 7). Although the obvious sources of contamination from the site have been removed, we did observe a sheen on the surface of water in the intermittent creek. We were not able to determine the source of the sheen.

In the past, surface water from the intermittent creek had measurable concentrations of site contaminants; however, since the intermittent creek was not used for recreational purposes, frequent contact with the water was unlikely. Thus, dermal contact with or incidental ingestion of water from the intermittent creek were not considered to be significant exposure pathways.

Big Walnut Run Creek is approximately one mile downstream from the site and is used for recreational purposes. Since water obtained from the intermittent creek between the site and Big Walnut Run Creek, prior to the source removal, did not contain any measurable levels of site contaminants, we have concluded that surface water downstream of the site (in the intermittent creek west of Hart Creosoting and in Big Walnut Run Creek) presents no public health hazard.

Evaluation of Possible Surface Soil Exposure Pathways

In 1993, TNRCC collected two soil samples from visually contaminated areas on the Hart Creosoting site. The results are shown in Appendix C Table 8 [10]. In 1994, Roy F. Weston collected five surface soil samples from the process area (Appendix C; Table 9) [1]. Several of the PAHs were found to exceed their respective HAC values.

In the past, on-site workers and possibly trespassers, may have come in contact with contaminatedsoil on the site; however, because of the general lack of appropriate exposure information we couldnot evaluate the public health significance of these past exposures. For workers, exposures wouldlikely have been comparable to those at other creosote-wood treatment facilities.

In the Fall of 1995, EPA buried the contaminated soils in a clay-lined and clay-capped structure. Currently, the capped area is inaccessible [4]. Since the potential for people to come in contact with contaminated soil on site has been eliminated, the contaminated surface soil currently poses no public health hazard.

Evaluation of Possible Air Exposure Pathway

Air sampling data were not available for our review and air releases were not documented during the time the site was operating. Volatilization of creosote constituents from the surface impoundments, processing area, and drip areas was possible during the time the facility was operating and prior to the enclosure of the contaminated sediments and soils in the clay-lined and clay-capped pit.

Due to the lack of historical air sampling data we could not assess the potential public health significance of inhalation of creosote constituents via this pathway. Since the site is no longer operating and source areas have been contained, we concluded that currently the air pathway poses no public health hazard.


Community Health Concerns

As part of the public health assessment process, ATSDR and TDH try to learn what concerns people in the area may have about the impact of the site on their health. Consequently, attempts are made to actively gather information and comments from people who live or work near the site. In an attempt to collect community health concerns related to the Hart Creosoting Company site, we contacted several different agencies and inpiduals by telephone. These agencies include the regional offices of the Texas Department of Health (TDH Region 4/5N), the Texas Natural Resource Conservation Commission (Region 10), and the U.S. Environmental Protection Agency (Region 6). In addition to these state and federal agencies we contacted local citizens and local health department staff from the Jasper-Newton County Public Health District. We did not identify any health concerns pertaining to the Hart Creosoting site.

Child Health Initiative

ATSDR's Child Health Initiative recognizes that the unique vulnerabilities of infants and children demand special emphasis in communities faced with contamination of their water, soil, air, or food. Children are at greater risk than adults from certain kinds of exposures to hazardous substances emitted from waste sites and emergency events. They are more likely to be exposed because they play outdoors and they often bring food into contaminated areas. They are shorter than adults, which means they breathe dust, soil, and heavy vapors close to the ground. Children are also smaller, resulting in higher doses of chemical exposure per body weight. The developing body systems of children can sustain permanent damage if toxic exposures occur during critical growth stages. Most importantly, children depend completely on adults for risk identification and management decisions, housing decision, and access to medical care.

ATSDR evaluated the likelihood for children living in the vicinity of the Hart site to be exposed to site contaminants at levels of health concern. ATSDR identified situations in which children who trespassed on the site in the past could have been exposed to site-related contaminants in soil. Due to a paucity of historical data we were not able to adequately assess the potential public health significance of these potential exposures. Currently, children are not likely to be exposed to contaminants in sediments or soils from the Hart Creosoting site since these have been consolidated in a clay-lined and clay-capped pit on the site and this area has been surrounded with a six-foot high intruder-resistant fence. In addition, children are not likely to be exposed to contaminants in sediments from the unnamed intermittent creek along and downstream of the Hart Creosoting site in sufficient quantities to pose a health threat.

Health Outcome Data

Health outcome data (HOD) record certain health conditions that occur in populations. These data can provide information on the general health of communities living near a hazardous waste site. It also can provide information on patterns of specified health conditions. Some examples of health outcome databases are tumor registries, birth defects registries, and vital statistics. Information from local hospitals and other health care providers also may be used to investigate patterns of disease in a specific population. TDH and ATSDR look at appropriate and available health outcome data when there is a completed exposure pathway or community concern. Due to a lack of completed exposure pathways and no identified community health concerns at this time, we did not review health outcome data.

Next Section     Table of Contents The U.S. Government's Official Web PortalDepartment of Health and Human Services
Agency for Toxic Substances and Disease Registry, 4770 Buford Hwy NE, Atlanta, GA 30341
Contact CDC: 800-232-4636 / TTY: 888-232-6348

A-Z Index

  1. A
  2. B
  3. C
  4. D
  5. E
  6. F
  7. G
  8. H
  9. I
  10. J
  11. K
  12. L
  13. M
  14. N
  15. O
  16. P
  17. Q
  18. R
  19. S
  20. T
  21. U
  22. V
  23. W
  24. X
  25. Y
  26. Z
  27. #