Natural Background Topsoil Arsenic Concentrations and Implications for Health SGVs
This study explores arsenic concentrations in New Zealand's topsoil, specifically within the Waikato region, and examines the implications for Soil Guideline Values (SGVs) concerning health. A comprehensive analysis of existing arsenic data highlights significant variability based on land use and soil type. This research identifies background concentrations of arsenic, showing averages around 4.5-6.0 mg/kg in natural settings, while agricultural and urban areas exhibit higher levels. The findings aim to inform environmental policy and land management guidelines.
Natural Background Topsoil Arsenic Concentrations and Implications for Health SGVs
E N D
Presentation Transcript
NATURAL BACKGROUND TOPSOIL ARSENIC CONCENTRATIONS AND SOME IMPLICATIONS FOR APPLYING SGVs(HEALTH) Daniel Moore Mathew Taylor Ministry for the Environment Environment Waikato
Introduction • Acknowledgements • Policy : toxicological vs. natural • Limited published arsenic data • Regional council data request
Timber Treatment Guidelines 1997 “The nominated criterion should not be less than a reasonable background concentration of arsenic. In this regard a value of, say, 30 mg/kg may be appropriate (Spier, 1997) notes that typically background concentrations of arsenic in New Zealand soils range from 2 to 30 mg/kg)”
Arsenic dataset • Collate existing data • Sample density, variability, confidence • Identification of data limitations • Assess key drivers of landscape-scale variation
Data analysis • Data quality • Standardised land use • Standardised soil type • Data desk • Pooled t-test
Data limitations • Variation in the sampling and analysis methodology • Poor land use classification • Representative Background data • Variation due to soil type • The effect of soil bulk density
Conclusions • Bush, indigenous forest, native = background • National As average 6.0 mg/kg • Background As average 4.5 mg/kg • Cropping, horticulture and urban land uses higher concentrations than background. • Waikato region statistical significance
Upcoming • Cadmium • Publish SGV comparisons • Data email: daniel.moore@mfe.govt.nz • Questions?