Mutagenic and carcinogenic potency of extracts of diesel and related environmental emissions: Study design, sample generation, collection, and preparation

A major diesel emissions research program has been initiated by the U.S. Environmental Protection Agency to assess the human health risk associated with increased use of diesel automobiles. This program is intended to establish the mutagenic and carcinogenic potency of complex organics associated with diesel particles as well as comparative particle-bound organics from other environmental emissions for which human epidemiological data are available. The mobile source samples selected for this study were collected from a heavy-duty diesel engine, a series of light-duty diesel passenger cars, and a gasoline catalyst automobile. The comparative source samples incorporated into the study were cigarette smoke condensate, coke oven emissions, roofing tar emissions, and benzo(a)pyrene. The samples were tested using three mutagenic assays and four carcinogenic assays as prescribed by a test matrix. This report describes the study design, particle generation, and sample collection and preparation. A brief summary of the bioassays is also included.     

The in-vitro response of pollen germination and tube length to different types of acidity

Pollen germination and tube growth are among the most sensitive responses to atmospheric pollution. Both these are inhibited by the acidity of the growth medium. Pollen grains from two species (Pinus cembra L. and Sambucus nigra L.) were germinated in media over a range of pHs (5.0, 4.5, 4.0, 3.5, 3.0 and 2.5) and six types of acidity (H(2)SO(4), HNO(3), H(2)SO(4): HNO(3) in 1:1, 2:1, 3:1 and 5:1 ratio). Pollen of the Gymnosperm is shown to be more resistant to acidity in the medium. Sulphuric acid alone and the ratio 2:1 with nitric acid are demonstrated to be the more harmful for P. cembra and S. nigra, respectively. The latter species was sensitive to all mixtures, particularly in respect to germination percentage.     

Oberflächennahe Rohstoffe und Öffentlichkeit

The public has been sensitized to the fact that due to the shortage of energy resources, mainly hydrocarbons, energy policy difficulties and the interrelated problems of nuclear energy, nuclear waste disposal and environmental protection, have developed. However, what is realized much less is the fact that mineral resources are also not available in unlimited amounts in some industrial nations, especially near-surface industrial minerals, whose prices are often very sensitive to transport costs. This can be explained only partly by geological conditions, but by limited access to the resources. By setting its goals too high, society risks in many respects the fulfillment of its desires for improving the standard of living.