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Although all chromite ore processing residue (COPR) sites near residential neighborhoods in Jersey City, New Jersey have undergone remediation, recent studies found widespread, but low levels of hexavalent chromium (Cr+6) in house dust both in Jersey City and in communities with no known sources of Cr+6. This study was designed as a follow-up to determine whether there is an association between current Cr+6 levels in house dust and urinary chromium concentrations in young children. Dust samples (N=369) were collected from 123 homes. The median Cr+6 concentration was 3.3 μg/g (mean±SD 5.2±7.5) and the median Cr+6 loading was 1.1 μg/m2 (1.9±3.1). These levels were not elevated compared with previously reported levels in background communities (median concentration=3.5 μg/g; median loading=2.8 μg/m2). Urinary chromium concentrations were measured in spot urine samples collected from 150 children, ages 3 months to 6 years. The median uncorrected urinary chromium concentration was 0.19 μg/l (0.22±0.16). Current urinary chromium concentrations were significantly lower than those previously reported before and during remediation (t-test; P<0.001). Urinary chromium concentrations were not significantly higher in homes with high (75th or 90th percentile) Cr+6 dust levels (concentration or loading) compared with other homes. Multiple linear regression was used to examine the relationship between Cr+6 levels (concentration and loading) in house dust and urinary chromium concentrations (uncorrected and specific gravity corrected). Contrary to pre-remediation studies, we did not find a positive association between Cr+6 levels in house dust and urinary chromium concentrations. The findings indicate that current Cr+6 levels in house dust are not positively associated with children's chromium exposure as measured by urinary chromium, and the children's exposure to Cr+6 in house dust is below the level that could be identified by urine sampling. [ABSTRACT FROM AUTHOR] more...

During much of the twentieth century, Jersey City, New Jersey was the leading center of chromate production in the United States. Chromate production produced huge volumes of chromium ore-processing residue containing many parts per million of hexavalent chromium. Starting in the 1990s, we undertook a series of studies to identify exposed populations, sources and pathways of exposure and the effectiveness of remediation activities in Jersey City. These studies revealed the effectiveness and success of the remediation activities. The sequence of studies presented here, builds on the lessons learned from each preceding study and illustrates how these studies advanced the field of exposure science in important ways, including the use of household dust as a measure of exposure to contaminants originating in the outdoor environment; development of effective and reproducible dust sampling; use of household dust to track temporal changes in exposure; understanding of the spatial relationship between sources of passive outdoor particulate emissions and residential exposure; use of focused biomonitoring to assess exposure under conditions of large inter-individual variability; and utility of linking environmental monitoring and biomonitoring. For chromium, the studies have demonstrated the use of Cr+6-specific analytical methods for measuring low concentrations of Cr+6 in household dust and understanding of the occurrence of Cr+6 in the background residential environment. We strongly recommend that environmental and public health agencies evaluate sites for their potential for off-site exposure and apply these tools in cases with significant potential as appropriate. This approach is especially important when contamination is widespread and/or a large population is potentially exposed. In such cases, these tools should be used to identify, characterize and then reduce the exposure to the off-site as well as on-site population. Importantly, these tools can be used in a demonstrable and quantifiable manner to provide both clarity and closure to concerned stakeholders. [ABSTRACT FROM AUTHOR] more...

Abstract: In contrast to Cr+3, Cr+6 is carcinogenic and allergenic. Although Cr+6 can occur naturally, it is thought that most soil Cr+6 is anthropogenic, however, the extent of Cr+6 in the background environment is unknown. Cr+6-containing chromite ore processing residue (COPR) from chromate manufacture was deposited in numerous locations in Jersey City (JC), New Jersey. In the 1990''s, significantly elevated concentrations of total Cr (Cr+6 +Cr+3) were found in house dust near COPR sites. We undertook a follow-up study to determine ongoing COPR exposure. We compared Cr+6 in house dust in JC to selected background communities with no known sources of Cr+6. Samples were collected from living areas, basements and window wells. Cr+6 was detected in dust from all JC and background houses. In the JC homes, the mean (±SD) Cr+6 concentration for all samples was 3.9±7.0μg/g (range: non-detect–90.4μg/g), and the mean Cr+6 loading was 5.8±15.7μg/m2 (range: non-detect–196.4μg/m2). In background homes, the mean Cr+6 concentrations of all samples was 4.6±7.8μg/g, (range, 0.05–56.6μg/g). The mean loading was 10.0±27.9μg/m2 (range, 0.22–169.3μg/m2). There was no significant difference between Cr+6 dust concentrations in Jersey City and background locations. Stratification by sample location within houses and sampling method gave similar results. Samples exceeding 20μg/g were obtained only from single wood surfaces in different homes. Lower concentrations in window well samples suggests transport from outside is not the major source of indoor Cr+6. Landscaping and groundcover may influence indoor Cr+6. There appears to be a widespread low level background of Cr+6 that is not elevated in Jersey City homes despite its historic COPR contamination. It is possible that house dust, in general, is a source of Cr+6 exposure with potential implications for persistence of chromium allergic contact dermatitis. [Copyright &y& Elsevier] more...