Genotoxicity of substances extracted from construction materials

Construction waste such as road pavement and concrete is estimated to constitute about 50% of the total industrial waste in Japan, and the recycling of such material has recently become a prominent topic among construction engineers. It has also been suggested that various types of industrial waste be utilized as components of construction materials. This paper investigates the environmental safety of certain materials in terms of the elutions and genotoxicities of these substances. The substances extracted from some materials, such as emulsifier, ash, and sediment, were found to have genotoxic characteristics. The dose-related responses of the various materials and their genotoxic strengths are shown. Received: June 16, 1998 / Accepted: September 7, 1999     

Statistical approach for the source identification of boron in leachates from industrial landfills

Boron has been found in high concentrations in leachates from landfills located throughout Japan. However, the source(s) of boron in the leachates, i.e., what kind of waste(s) releases this element into the leachate, has not been clarified. In this study, boron concentrations in leachates from 48 industrial landfills were evaluated, in relation to the categories of waste constituting the landfill in each of the sites, by multiple regression analysis. The multiple regression analyses were carried out using the log-transformed boron concentration as a dependent variable and each of 19 categories of industrial waste (according to the Japanese Waste Disposal and Public Cleansing Law) as independent variables. Stepwise variable selection was employed in the analyses. Although the significant variable(s) selected varied according to the data sets analyzed (viz., data sets from least controlled landfill sites, from controlled landfill sites, and from both), cinders, slag, and waste plastics emerged as wastes with positive partial regression coefficients that significantly explained the boron levels in the leachates. These results indicated that cinders, slag, and waste plastics were the sources of high concentrations of boron in the leachates. The results of the present exploratory statistical analyses warrant a systematic survey of the boron contents of, and leachability from, cinders, slag, and waste plastics. Received: January 17, 2000 / Accepted: July 24, 2000     

Bisphenol A in hazardous waste landfill leachates

The levels of bisphenol A in hazardous waste landfill leachates collected in Japan in 1996 were determined by gas chromatograph/mass spectrometer (GC/MS). Bisphenol A was found in seven of 10 sites investigated. All the hazardous waste landfills with leachates contaminated by bisphenol A were controlled. The concentrations of bisphenol A ranged from 1.3 to 17,200 microg/l with a median concentration of 269 microg/l. The source of bisphenol A in landfill leachates may be the waste plastics in waste landfill. The concentrations of bisphenol A in some samples exceeded the EC50 or LC50 levels for aquatic biota. Landfill leachates may be a significant source of bisphenol A found in the environment.