Levels of hexachlorocyclohexanes in agricultural environment of Sacco river valley.

Aim of this trial was to verify the occurrence and the distribution of hexachlorocyclohexanes (HCHs) in soil, sediment, straw, alfalfa, other animal feed grown in farms with contaminated soil. In the present study two years of monitoring activity in the province of Roma and Frosinone was reported. Experimental trial in two contaminated sites was carried out on uptake and translocation of HCHs in maize and alfalfa. In 19 sites soil, forage and weed has been collected for two years, soil samples consisted in cores of 40 cm to test the presence of HCHs at different deep. The analytical determinations in soil and plant samples were carried out by gas liquid chromatography with electron capture detector and confirmed by mass detector. In the first year (2005- 2006) 68% of soil samples were contaminated (HCHs > LOQ) and 3% of vegetable samples. In the second year (2006- 2007) 42% of soil samples resulted positive and 26% of vegetable matrix. In particular B hexacyclohexane was detected in wheat stem (0.037 mg/kg) with a soil contamination of 0.039 mg/kg and in alfalfa (0.012 mg/kg) with presence in soil of 0.004 mg/kg. Experimental trials on maize evidenced a translocation factor for this isomer stem/soil of 0.006 mg/kg ? and for grain of 0.005 mg/kg. On alfalfa translocation factor root/soil was 0.01 and shot/soil 0.009. A propose to calculate the threshold value of soil contamination to admit crop grown destined to animal feed, would be based on HCHs LOD values weighted with translocation factor.