Environmental Pollution Series A, Ecological and Biological最新文献

Contamination of human milk with residues of organochlorine insecticides represents a major environmental problem. Four mothers were the subjects of a 5-month follow-up study of the weekly variations in the levels of these pollutants in their milk. Residues detected and confirmed were those of γ-HCH, heptachlor, heptachlor epoxide, chlordane, aldrin, dieldrin and isomers and metabolites of DDT. Fluctuation in the residue levels was obvious due to variations in the daily dietary intake of residues and variations in fat content of maternal milk.

Bacterial densities of sewage from five hospitals in Baghdad city from September 1983 to August 1984 were measured.

The average numbers of total coliform, faecal coliform, faecal streptococci, Staphylococci, Klebsiella sp. and fluorescent Pseudomonas sp. were $\text{20·94 × 10}{}^3\text{, 7·49 × 10}{}^2\text{, 8·00 × 10}{}^4\text{, 3·4 ×1o}{}^4\text{, 7·10 ¢ 10}{}^4$ and 4·16 × 10⁵ cells ml⁻¹, respectively. A remarkable decrease was observed from December to March, as well as regular changes during other seasons, in the numbers of total coliforms, Kelbsiella sp. and fluorescent Pseudomonas. Faecal coliform, faecal streptococci and Staphylococci did not show such a profile. Specialised hospitals contained higher counts of total coliform than general hospitals.

Two Salmonella serotypes were identified—S. albany and S. senftenberg.

Male specimens of H. fossilis were exposed to a concentration of 8 mg litre⁻¹ of malathion in their aquarium water for 16 days during the early post-spawning phase. Its effects on glycogen of liver, testes and muscle, glucose and free fatty acids (FFA) in plasma, spleeno-somatic index (SSI), red blood corpuscle (RBC) and haemoglobin (Hb) were examined. Reduced levels of liver and muscle glycogen, associated with increasing plasma glucose, were noticed after 4 and 8 days of treatment but, after 16 days, a recovery was observed. Testicular glycogen did not respond to malathion exposure. Plasma FFA was also unchanged for 4 and 8 days of treatment but a higher level was recorded after 16 days' exposure. RBC and Hb were reduced following the 4-day exposure; however, no apparent change in their level was observed after 8 and 16 days' exposure. The SSI was also reduced during the 4- and 8-day treatments but 16 days' exposure caused the level to return to normal. Thus, this study demonstrates that, after prolonged exposure, H. fossilis develops a tolerance and partially recovers from the stress condition. In the initial stages carbohydrate was used as an energy source to meet the stress situation, while, in the later phase of exposure, FFA served as the major source of energy.

The current state of health of Norfolk Island pines, Araucaria heterophylla (Salisb.) Franco, on the coast of metropolitan Sydney was evaluated in 1983/84 by surveying 20 trees, in each of six regions, the trees being selected from larger numbers surveyed during 1973/74. It was found that crown density was inversely related to foliage concentrations of Na⁺ and Cl⁻ which were themselves positively correlated. It is thought that this uptake is mediated by surfactants which enter the sea by discharge from coastal sewage outfalls. Since the previous study, crown density has decreased in three of the six sampling regions, these reflecting increased volumes of sewage discharge. In the other three areas, crown densities had not changed significantly.

The fluoride pathway from an aluminium reduction plant was investigated by examining fluoride accumulation in the species of many invertebrate groups. Previous workers had examined only a few groups. All groups showed increasing accumulation from control to medium exposure to high exposure zones. In the high exposure zone, the scavengers, millipedes and woodlice, had the greatest mean accumulation of approximately 1100 μg Fg⁻¹. The predatory spiders (393 μg Fg⁻¹) and harvestmen (258 μg Fg⁻¹) were next. These were followed by slugs and snails (190 μg Fg⁻¹) feeding on decaying and fresh plant material, earthworms (184 μg Fg⁻¹) feeding on organic material in the soil, the omnivorous beetles (50 μg Fg⁻¹) and the predatory centipedes (48 μg Fg⁻¹). The herbivorous grasshoppers contained least (20 μg Fg⁻¹). The overall sequence of increasing fluoride was: herbivores—omnivores—predators—scavengers. In some groups, such as beetles, the levels were comparatively low, but the same sequence occurred. The fluoride content of each species is important in the transfer of fluorides to predators, but does not necessarily reflect the level of involvement in the fluoride pathway through the ecosystem.

Trace elements (Hg, Se, Cd, Pb and Zn) and chlorinated hydrocarbons (hexachlorobenzene, pp′DDE and PCBs) were measured in eggs and tissues of a pelagic seabird (Calonectris diomedea) collected in one station of the eastern Atlantic and in three stations of the Mediterranean Sea. Mercury and chlorinated hydrocarbons were much higher in tissues and eggs of the Mediterranean specimens than in those from the Atlantic. Atlantic eggs had thicker shells than Mediterranean ones. In all the specimens selenium levels in the liver were strongly correlated with mercury; cadmium levels were high in the kidney and, to a lesser extent, in the liver. PCB isomers and congeners were studied in detail.

Changes in the radiation balance (albedo) of maize polluted with cement dust were measured at the Agrometeorological Research Station, Keszthely, Hungary, during 1982–1984. The radiation intake of polluted plants was increased, and this increased plant temperature and evapo-transpiration. Higher radiation values did not have a positive effect on dry matter production; in fact, fertilisation was found to deteriorate and yields on average decreased by 16·2% during the three years.