Evidence for long-term changes in the soil composition of selected organic compounds, brought about by exchanges with the atmosphere, is briefly reviewed. In the case of some compounds - such as benzo(a)pyrene and octachlorodibenzo-p-dioxin, soils may be significant long-term environmental sinks for atmospherically-derived material. In other cases - such as phenanthrene and some of the lighter PCBs, de-gassing or volatilisation from soil back to the air can occur under certain conditions. Hence the soil may act as a "short-term" sink, and a potential source to atmosphere. Indeed, for some 'semi-volatile' compounds used in large quantities in the past - such as PCBs, soil outgassing may actually be an extremely important source to contemporary air. Furthermore, soil outgassing from areas of former high use may provide an important driving mechanism for continued "global cycling" of a range of semi-volatile organochlorine compounds.

A waste-oil contaminated site situated near a river is supposed to be cleaned-up by means of different but complementary methods. On the basis of a research project, target values have been developed in close cooperation between the participant parties for the saturated and the unsaturated soil layers. The clean-up targets are introduced and discussed.

The present study investigated that the potential of soil or foliar applied 15 mg/L zinc oxide quantum dots (ZnO QD, 11.7 nm) to enhance pumpkin (Cucurbita moschata Duch.) growth and biomass in comparison with the equivalent concentrations of other sizes of ZnO particles, ZnO nanoparticles (ZnO NPs, 43.3 nm) and ZnO bulk particles (ZnO BPs, 496.7 nm). In addition, ZnSO4 was used to set a Zn²⁺ ionic control. For foliar exposure, ZnO QD increased dry mass by 56% relative to the controls and values were 17.3% greater than that of the ZnO NPs particles. The cumulative water loss in the ZnO QD treatment was 10% greater than with ZnO NPs, suggesting that QD could better enhance pumpkin growth. For the root exposure, biomass and accumulative water loss equivalent across all Zn treatments. No adverse effects in terms of pigment (chlorophyll and anthocyanin) contents were evident across all Zn types regardless exposure routes. Foliar exposure to ZnO QD caused 40% increases in shoot Zn content as compared to the control; the highest Zn content was evident in the Zn²⁺ ionic treatment, although this did not lead to growth enhancement. In addition, the shoot and root content of other macro- and micro-nutrients were largely equivalent across all the treatments. The contents of other nutritional compounds, including amino acids, total protein and sugar, were also significantly increased by foliar exposure of ZnO QD. The total protein in the ZnO QD was 53% higher than the ZnO particle treatments in the root exposure group. Taken together, our findings suggest that ZnO QDs have significant potential as a novel and sustainable nano-enabled agrichemical and strategies should be developed to optimize benefit conferred to amended crops.