No abstract

A field study of industrial organic contaminant uptake, in particular PCB uptake, by growing crops was conducted during 1990 at the St. David Coal Refuse Pile Reclamation Site, Fniton County, Illinois. The site had received one-time applications in 1987 of 785, 1570 and 3360 Mg ha-~ dry wt. of Chicago municipal sewage sludge. Corn (Zea mays L.), cabbage ( Brassica oleracea capitata L.), and carrot (Daucus carota L.) were grown on the sludge treatments and soil (i.e., sludge treated coal refuse) and plant samples were analyzed. Mean PCB concentratious in the soils were < 4 mg kg-~ dry wt. and there was no consistent effect on them of sludge application rate. Measurements on the 3360 Mg ha-~ dry wt. of sludge treatment soil indicated that several organochlorine pesticides occurred at concentrations _< 217 lag kg-~ dry wt. and several polynuclear aromatic hydrocarbons occurred at <1 to 3 mg kg -~ dry wt. Mean PCB concentrations in the plant materials were <300 pg kg -~ dry wt., however, there were differences among and within crops. Concentrations decreased in the order: carrot peels > carrot tops > cabbage wrapper and inner leaves > carrot core > corn ear leaf and stover > corn grain. There was insignificant PCB in corn grain. Except for cabbage wrapper leaves, the PCB concentrations in plant materials were not related to those in soil. Soil PCB concentrations accounted for 24% of the variance in cabbage wrapper leaf PCB concentrations and the bioconcentration factor (mg PCB kg -~ dry wt. of leaf/kg PCB ha -~ dry wt. of soil) was 0.0042. There was no detection of organochlorine pesticides in plant materials grown on the 3360 Mg ha-~ dry wt. of sludge treatment soil and, except for indole and isophorone, only trace amounts of a very few other organic contaminants were observed in the plant materials. Indole ranging from no detection to 52 mg kg-~ dry wt. may have been a natural constituent of cabbage. Isophorone ranging from 14 to 79 mg kg-d ry wt. was observed in three samples of cabbage wrapper leaves and its source is unknown. Despite the very large rates of Chicago sludge employed in this study, findings indicated that they did not (i) result in high levels of organic contamination in the treated coal refuse, and (ii) represent a significant organic contaminant hazard to the quality for food and feedstutfs of crops grown on the treated coal refuse.

No abstract

Synopsis Fertilizers containing nitrogen and phosphorus gave a larger increase in yield of rape than of wheat or flax. This appeared to be due to the more rapid uptake and the greater requirement of rape for these elements.

A comparison of several extraction methodologies for the analysis of base-neutral and acid organic contaminants (EPA priority pollutants) in municipal sludge was conducted. Sludge was spiked with selected contaminants and extracted wet and following air-drying by a variety of techniques such as dilution, centrifuge extraction, Soxhlet extraction and high speed mixing (PolytronR, WaringR and ultrasonic probe). All of the techniques produced variable results. Recoveries of spiked compounds ranged from 0 to > 100% and, in general, the relative standard deviations ranged from 20 to 50%. Extraction of wet sludge using high speed mixing was considered to be the most satisfactory technique. Based on analyses of 15 municipal sludges derived mainly from industrial centres, it is suggested that agricultural utilization of Canadian sludges probably does not represent a significant organic contaminant hazard to the food chain. Organic contaminant concentrations in the sludges generally were < 10 mg kg-1 dw. Phthalate esters in several sludges and polynuclear aromatic hydrocarbons (PAHs) in Hamilton sludge exceeded 10 mg kg-1 dw; however, phthalate esters are readily degraded in soil and the Hamilton sludge is incinerated. "Acceptable" organic contaminant concentrations in sludges for use on pasture and arable lands are suggested. However, it is recommended that further analytical research be undertaken to develop more accurate and precise methods for measuring organic contaminants in municipal sludge and that an expanded program of sampling and analysis be undertaken to provide more reliable information concerning organic contaminant concentrations in Canadian sludges.