TOXICOLOGICAL PROFILE FOR CHROMIUM - Davidborowski.com

CHROMIUM 3105. POTENTIAL FOR HUMAN EXPOSUREThe following categories of possible data needs have been identified by a joint team of scientists fromATSDR, NTP, and EPA. They are defined as substance-specific informational needs that if met wouldreduce the uncertainties of human health assessment. This definition should not be interpreted to meanthat all data needs discussed in this section must be filled. In the future, the identified data needs will beevaluated and prioritized, and a substance-specific research agenda will be proposed.5.8.1 Identification of Data NeedsPhysical and Chemical Properties. As seen in Section 3.2, the relevant physical and chemicalproperties of chromium and its compounds are known (Hartford 1979; Weast 1985) and prediction ofenvironmental fate and transport of chromium in environmental media is possible. However, the physicalor chemical forms and the mode by which chromium(III) compounds are incorporated into biologicalsystems are not well characterized. The determination of the solubilities of hexavalent chromiumcompounds in relevant body fluids (e.g., the solubility of chromates in lung fluid) may also be helpful.Production, Import/Export, Use, Release, and Disposal. Knowledge of a chemical'sproduction volume is important because it may indicate environmental contamination and humanexposure. If a chemical's production volume is high, there is an increased probability of generalpopulation exposure via consumer products and environmental sources, such as air, drinking water, andfood. Data concerning the production (Hartford 1979; SRI 1997), import (NTDB 1998), and use (CMR1988; EPA 1984a; IARC 1990; USDI 1988a) of commercially significant chromium compounds areavailable. It does not appear that chromium is used to process foods for human consumption or is addedto foods other than diet supplements. Consumer exposure to chromium occurs mostly from natural food(Bennett 1986; EPA 1984a; Kumpulainen et al. 1979), but this exposure will increase particularly forpeople who consume acidic food cooked in stainless steel utensils (Anderson 1981; EPA 1984a).Exposure to chromium occurs to a much lesser extent from products such as toners of photocopyingmachines, some wood treatment chemicals, and through other chromium-containing consumer products(CMR 1988; EPA 1984a; IARC 1990; USDI 1988a).The TRI97 (1999), which became available in 1999, has been used in this profile. As can be seen inTable 5-2, the largest amount of chromium from production and user facilities is disposed of on land ortransferred to an off-site location. More detailed site-and medium-specific (e.g., air, water, or soil) releasedata for chromium that is disposed of off-site are necessary to assess the exposure potential to thesecompounds from different environmental media and sources. There are EPA guidelines regarding the