TY - JOUR
T1 - A critical evaluation of the use and ‘misuse’ of As and Pb bioaccessibility data in human health risk assessments
AU - Dean, John
AU - Amaibi, Patrick
AU - Okorie, Alexander
AU - Entwistle, Jane
N1 - Funding information: The authors wish to thank the Niger Delta development Commission (NDDC/DEHSS/2012PGFS/RIV/0016), Nigeria, for funding the research at sites 1 and 2, Natalie Kennedy for providing support for PA to undertake work as sites 1 and 2, and Grant Richardson for providing support to AO to undertake work at Site 3. We are also grateful to Mr. Gordon Forrest and Mr. Dave Thomas, Northumbria University, for their technical assistance.
PY - 2020/10/1
Y1 - 2020/10/1
N2 - With the now widescale reporting of oral bioaccessibility data at contaminated sites, following our investigation of three sites (one public open space and two residential) for As and Pb contamination, a critical evaluation of the application and utility of such bioaccessibility testing was undertaken to better inform future use. Mean As and Pb soil levels across the sites varied between 12.5 and 24,900 mg/kg and 149–5930 mg/kg, respectively. Using the Unified Bioaccessibility Method (UBM) for in vitro bioaccessibility testing the highest bioaccessible concentrations were identified in the gastric phase. At site 1, a residential urban garden site the maximum bioaccessible As was 50.2% while the maximum bioaccessible Pb was 64.8%; similarly in site 2, also a residential urban garden site the maximum bioaccessible As was 38.72% while the maximum bioaccessible Pb was 66.0%. However, at site 3, a public open space site, the maximum bioaccessible As was 29.7% while the maximum bioaccessible Pb was 38.4%. Using the appropriate soil screening values and recommended statistical testing, we highlight that the use of bioaccessibility testing was unnecessary at sites 1 and 2 (residential urban garden sites), while at site 3 the value of oral bioaccessibility testing is highlighted as part of a ‘lines of evidence approach’ to support the site's specific risk assessment. We need to move away from the uncritical, blanket application of oral bioacessibility testing and strategically target where the results of these data add real value to site determination.
AB - With the now widescale reporting of oral bioaccessibility data at contaminated sites, following our investigation of three sites (one public open space and two residential) for As and Pb contamination, a critical evaluation of the application and utility of such bioaccessibility testing was undertaken to better inform future use. Mean As and Pb soil levels across the sites varied between 12.5 and 24,900 mg/kg and 149–5930 mg/kg, respectively. Using the Unified Bioaccessibility Method (UBM) for in vitro bioaccessibility testing the highest bioaccessible concentrations were identified in the gastric phase. At site 1, a residential urban garden site the maximum bioaccessible As was 50.2% while the maximum bioaccessible Pb was 64.8%; similarly in site 2, also a residential urban garden site the maximum bioaccessible As was 38.72% while the maximum bioaccessible Pb was 66.0%. However, at site 3, a public open space site, the maximum bioaccessible As was 29.7% while the maximum bioaccessible Pb was 38.4%. Using the appropriate soil screening values and recommended statistical testing, we highlight that the use of bioaccessibility testing was unnecessary at sites 1 and 2 (residential urban garden sites), while at site 3 the value of oral bioaccessibility testing is highlighted as part of a ‘lines of evidence approach’ to support the site's specific risk assessment. We need to move away from the uncritical, blanket application of oral bioacessibility testing and strategically target where the results of these data add real value to site determination.
KW - Arsenic
KW - Human health risk assessment
KW - Lead
KW - Oral bioaccessibility
KW - Soil
UR - http://www.scopus.com/inward/record.url?scp=85087947058&partnerID=8YFLogxK
U2 - 10.1016/j.envres.2020.109915
DO - 10.1016/j.envres.2020.109915
M3 - Article
SN - 0013-9351
VL - 189
SP - 1
EP - 9
JO - Environmental Research
JF - Environmental Research
M1 - 109915
ER -