API PUBL 4733-2004 pdf free download

API PUBL 4733-2004 pdf free download.Risk-Based Screening Levels for the Protection of Livestock Exposed to Petroleum Hydrocarbons.
Consumption of petroleum hydrocarbons by livestock has been found to lead to a range of health problems, including neurotoxicity (Coppock et al. 1995; Khan et al. 1995), fetal toxicity (Coppock et al. 1995), damage to the gastrointestinal tract (Coppock et al. 1996), respiratory system, kidney, and liver (Meadows and Waltner-Toews 1979; Edwards 1985a; Coppock et al. 1995; Coppock et al. 1996; Stober 1962). Petroleum ingestion has also been linked to anorexia (Edwards and Zinn 1979), lethargy (Meadows and Waltner-Toews 1979; Edwards 1985b), and fatal poisoning in cattle (Edwards and Zinn 1979; Meadows and Waltner-Toews 1979; Edwards and Gregory 1991). The purpose of this study was to develop toxicity values and screening guidelines for evaluating risks to livestock from exposure to petroleum hydrocarbons. This report addresses how to: (1) determine whether livestock should be included in a risk evaluation, and (2) estimate risks of petroleum hydrocarbon exposures to livestock. In this report, the approach used to develop toxicity values and screening guidelines for livestock from petroleum hydrocarbon exposures was divided into two steps: · The first step included evaluation of the potential for exposure through the development of a conceptual site model (CSM). · The second step included development of Toxicity Reference Values (TRVs) and Risk-Based Screening Levels (RBSLs) for the protection of livestock. This report focused on whole crude oil and its toxicologically important constituents (i.e. benzene, toluene, ethylbenzene, and xylene [BTEX] and polycyclic aromatic hydrocarbons [PAHs]). Metals can also be present in petroleum products, but they are generally not found at high enough concentrations to provide a significant health risk (Magaw et al., 1999) and therefore metals are not addressed in this report. A conceptual site model (CSM) identifies complete and potentially complete exposure pathways and receptors to be considered in a risk assessment. If no complete significant pathway(s) exist for exposure of livestock to petroleum hydrocarbons, a screening-level risk evaluation for livestock is not necessary. By definition, if there is little to no significant exposure to a potentially toxic compound, there is little to no likelihood of significant unacceptable risk to the receptor from that compound. A CSM was developed as presented in Figure 1 to assess the potential for exposures to livestock and the need for a risk evaluation. Components of a CSM generally include receptor evaluation and exposure pathway evaluation, which are described below. 3.1 Receptor Evaluation Livestock that are potentially vulnerable to toxic effects of petroleum hydrocarbons include animals that could ingest significant quantities of soil, water, and/or food in oil-contaminated areas. Access to the contaminated areas is key; cattle, sheep, goats, and horses that forage in pasture areas are more likely to be potential receptors, while species that are raised in more confined and controlled conditions, such as chickens or pigs, would have less chance of exposure to petroleum hydrocarbons. Outside of the United States, other types of livestock animals may also be exposed to petroleum compounds, such as camels, llamas, oxen, etc. It was assumed that exposures to these receptors would be similar to those of typical livestock in the United States based on similarities in body weights and feeding habits. 3.2.3 Direct Ingestion Cattle may directly ingest crude oil and other petroleum compounds from pools of oil formed by leaking pipelines or storage tanks (Edwards and Zinn 1979; Coppock et al. 1995; CCME 2000) due to curiosity (particularly in young calves; Edwards 1985b), or to add salt to their diet (Edwards 1985b, Coppock et al. 1995). Reported cases include steers consuming petroleum distillate, drinking from a slush pit, and drinking petroleum from puddles near a tank battery (Edwards and Zinn 1979). Oil and natural gas industry guidance (API 1997) and many regulatory agencies (e.g., the Railroad Commission of Texas 1993) stress the importance of removing free-oil accumulations on the ground that animals could potentially ingest. 3.2.4 Dermal Absorption Dermal absorption of petroleum hydrocarbons in livestock is considered a minor exposure pathway because of their thick coats (CCME 2000). While methods are available to assess dermal exposure to humans, data necessary to estimate dermal exposure are generally not available for livestock or wildlife (EPA 1993). Additionally, dermal exposure has been shown to be negligible for most terrestrial mammals (EPA 2000).