Petroleum hydrocarbons human health

There are many recommended sampling protocols (Table 6.2). The sampling methods used for petroleum hydrocarbons are generally thought of as methods for determination of the total petroleum hydrocarbons. In part due to the complexity of the components of the total petroleum hydrocarbons fractions, little is known about their potential for health or environmental impacts. As gross measures of petroleum contamination, the total petroleum hydrocarbons data simply show that petroleum hydrocarbons are present in the sampled media. Measured total petroleum hydrocarbons values suggest the relative potential for human exposure and therefore the relative potential for human health effects. 

Weisman, W. 1998. Analysis of Petroleum Hydrocarbons in Environmental Media. Total Petroleum Hydrocarbons Criteria Working Group Series, Vol. 1. Amherst Scientific Publishers, Amherst, MA.(See also Vol. 2, Composition of Petroleum Mixtures, 1998 Vol. 3, Selection of Representation Total Petroleum Hydrocarbons Fractions Based on Fate and Transport Considerations, 1997 Vol. 4, Development of Fraction-Specific Reference Doses and Reference Concentrations for Total Petroleum Hydrocarbons, 1997 and Vol. 5, Human Health Risk-Based Evaluation of Petroleum Contaminated Sites, Implementation of the Working Group Approach, 1999.)... 

Pharmacologically based pharmacokinetic (PBPK) models have also been incorporated into the assessment of responses to mixtures of some substances where interactions may occur. This was suggested for application in assessing human health risks of contaminants in drinking water (Krishnan et al. 1997) on the basis that most interactions between organic substances occur as a result of induction or inhibition of metabolism. This has been applied in predicting the maximal likely interaction in mixtures of chlorinated and nonchlorinated hydrocarbons (Haddad et al. 2000) and aromatic petroleum hydrocarbons (Haddad et al. 1999). Metabolic and other data are required for PBPK models, and, as these may only be available for a few organisms in the environment, they are not yet widely used for extrapolation. 

Agency for Toxic Substances and Disease Registry (ATSDR). 1999. Toxicological Profile for Total Petroleum Hydrocarbons (TPH). Atlanta, GA US Department of Health and Human Services, Public Health Service. 

Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) (1999) Human Health Risk-Based Evaluation of Petroleum Release Sites Implementing the Working Group Approach, vol. 5. Amherst, MA Amherst Scientific Publishers. 

These experts collectively have knowledge of total petroleum hydrocarbons physical and chemical properties, toxicokinetics, key health end points, mechanisms of action, human and animal exposure, and quantification of risk to humans. All reviewers were selected in conformity with the conditions for peer review specified in Section 104(i)(13) of the Comprehensive Environmental Response, Compensation, and Liability Act, as amended. 

Many methods are available for analysis of petroleum hydrocarbon products, particularly in water and soil matrices. The current literature includes a number of studies that document the performance and limitations of the commonly used methods. Method modifications and new methods are being investigated to provide better information about the petroleum component content of environmental samples. However, the available analytical methodology alone may not provide adequate information for those who evaluate the movement of petroleum components in the environment or evaluate the health risks posed to humans (Heath et al. 1993a). 

Stoddard solvent is a petroleum distillate mixture of C7-C12 hydrocarbons, approximately 80-90% aliphatics (30-50% linear and branched alkanes, and 30-40% cyclic alkanes) and 10-20% aromatics (not PAHs). It is similar to white spirits, which is also included in the toxicological profile on Stoddard solvent (ATSDR 1995b). For additional detail, see Section 3.2 and Table E-2.b. Data regarding the health effects of Stoddard solvent in either humans or animals are limited and were judged inadequate for MRL development. Upper respiratory irritant effects were seen in animals exposed by inhalation for acute and intermediate durations these appear to be the most sensitive effects by the inhalation route. Male rat nephropathy has been reported in intermediate inhalation studies, but is not considered relevant to human health. No oral studies were located. Information on the potential carcinogenicity of Stoddard solvent is inadequate. 

Verhaar et al. (1997), however, recently reported on progress in developing PBPK/PD models for use in assessing human health risks from exposure to JP-5, a Navy Jet petroleum fuel containing a complex mixture of hydrocarbons in the C9-C18 range. Verhaar et al. (1997) noted that their in-progress development of a PBPK/PD model for JP-5 is focused on the prediction of kinetics of JP-5 components in relevant tissues after acute inhalation exposure and the resultant toxicity (neurological effects linked to the dissolution of xenobiotic chemicals in the membrane of nerve cells). Verhaar et al. (1997) discussed how the development of PBPK/PD model(s) for complex mixtures involves ... 

Scientific research confirms that biofuel has a less harmful effect on human health than petroleum fuel. Biofuel emissions have decreased levels of polycyclic aromatic hydrocarbons (PAHs) and nitrited PAH compounds (nPAH), which have been identified as cancer causing compounds. Test results indicate that PAH compounds were reduced by 50-85%. Targeted nPAH compounds were reduced by 90%. Biofuel is nontoxic and biodegradable. In addition, the flash point (the lowest temperature at which it can form an ignitable mix with air) is 300° F, well above petroleum fuel s flashpoint of 125°F. 

Petroleum hydrocarbons are a mixture of many substances. The results of petroleum analysis depend as much on the analytical method as the petroleum. As long as everyone works to a common definition there is no problem. The Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) convened in 1993 to develop scientifically defensible information for establishing soil cleanup levels that are protective of human health at petroleum contaminated sites. The TPHCWG compiled their data and analytical efforts into five volumes that can be accessed at http //www.aehs.com/publications/catalog/ contents/tph.htm ... 

Polynuclear aromatics are hydrocarbons containing more than one fused benzenoid ring. These substances primarily occur in coal, coal tar, heavy oil, diesel fnel and many petroleum products. They are also found in soils, sediments, solid wastes, many wastewaters, emission from indnstrial boilers and tobacco smoke at trace concentrations. In the PAH class, U.S. EPA has hsted 16 compounds as priority pollutants in potable water and wastewater and 22 componnds in soil and solid wastes. Except naphthalene most PAH compounds have little commercial applications. However, they may be generated from various sources or industrial operations the exposure to which may pose risk to human health. Many PAHs may cause cancers, affecting a variety of tissues. However, only benzo[a]pyrene is a potent human carcinogen, while naphthalene, benzo[a]anthracene. 

Petroleum hydrocarbons contain a wide range of substances that are potential health hazards. These include aliphatic compounds, monocyclic aromatics, polycyclic aromatics, and heavy metals. Most petroleum products have an objectionable taste and odor well below the level that might induce chronic toxicity in humans. Thus, the most frequently reported symptoms of exposure are relatively mild and include nausea, vomiting, and diarrhea. 

TPH is defined as the measurable amount of petroleum-based hydrocarbon in an environmental media. It is, thus, dependent on analysis of the medium in which it is found (Gustafson 1997). Since it is a measured, gross quantity without identification of its constituents, the TPH "value" still represents a mixture. Thus, TPH itself is not a direct indicator of risk to humans or to the environment. The TPH value can be a result from one of several analytical methods, some of which have been used for decades and others developed in the past several years. Analytical methods are evolving in response to needs of the risk assessors. In keeping with these developments, definition of TPH by ATSDR is closely tied to analytical methods and their results. The ATSDR approach to assessing the public health implications of exposure to TPH is presented in Section 2.3. 

API. 1976. Detectability and irritability of hydrocarbons in human subjects. Final report to American Petroleum Institute. Contract no. U-15-14-PS-5. Department of Environmental Health, College of Medicine, University of Cincinnati, Cincinnati, OH. 

---