Volumes 518–519, 15 June 2015, Pages 507–517
Metal contamination of home garden soils and cultivated vegetables in the province of Brescia, Italy: Implications for human exposure
Highlights
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- We assessed metal concentrations in 3 areas of varying ferroalloy activity.
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- Measurements utilized XRF, aqua regia, and modified BCR sequential extraction.
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- Al, Cd, Fe, Mn, Pb, and Zn were higher in home gardens near ferroalloy plants.
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- Over 60% and 10% of spinach samples exceeded maximum Pb and Cd European standards.
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- Thorough washing is recommended when consuming vegetables from ferroalloy areas.
Abstract
Background
For
the past century, ferroalloy industries in Brescia province, Italy
produced particulate emissions enriched in manganese (Mn), lead (Pb),
zinc (Zn), copper (Cu), cadmium (Cd), chromium (Cr), iron (Fe), and
aluminum (Al). This study assessed metal concentrations in soil and
vegetables of regions with varying ferroalloy industrial activity
levels.
Methods
Home gardens
(n = 63) were selected in three regions of varying ferroalloy plant
activity durations in Brescia province. Total soil metal concentration
and extractability were measured by X-Ray Fluorescence (XRF), aqua regia
extraction, and modified Community Bureau of Reference (BCR) sequential
extraction. Unwashed and washed spinach and turnips cultivated in the
same gardens were analyzed for metal concentrations by flame atomic
absorption spectrometry.
Results
Median
soil Al, Cd, Fe, Mn, Pb, and Zn concentrations were significantly
higher in home gardens near ferroalloy plants compared to reference home
gardens. The BCR method yielded the most mobile soil fraction (the sum
of extractable metals in Fractions 1 and 2) and all metal concentrations
were higher in ferroalloy plant areas. Unwashed spinach showed higher
metal concentrations compared to washed spinach. However, some metals in
washed spinach were higher in the reference area likely due to history
of agricultural product use. Over 60% of spinach samples exceeded the 2-
to 4-fold Commission of European Communities and Codex Alimentarius
Commission maximum Pb concentrations, and 10% of the same spinach
samples exceeded 2- to 3-fold maximum Cd concentrations set by both
organizations. Turnip metal concentrations were below maximum standard
reference values.
Conclusions
Prolonged
industrial emissions increase median metal concentrations and most
soluble fractions (BCR F1 + F2) in home garden soils near ferroalloy
plants. Areas near ferroalloy plant sites had spinach Cd and Pb metal
concentrations several-fold above maximum standard references. We
recommend thorough washing of vegetables to minimize metal exposure.
Keywords
- Metal;
- Phytoavailability;
- Ferroalloy industry emissions;
- Vegetables;
- Plant uptake;
- Modified BCR sequential extraction procedure;
- Brescia;
- Italy
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