Exposure of garbage truck drivers and maintenance personnel at a waste handling centre to polycyclic aromatic hydrocarbons derived from diesel exhaust

Exposure to diesel exhaust was evaluated in summer and winter by measuring vapour and particle phase polycyclic aromatic hydrocarbons (PAHs). Fifteen PAHs were simultaneously determined from the air samples obtained from truck drivers collecting household waste and maintenance personnel at a waste handling centre. The major compounds analysed from the personal air samples of exposed workers were naphthalene, phenanthrene and fluorene. The total PAH exposure (sum of 15 PAHs) of garbage truck drivers ranged from 71 to 2,660 ng m(-3) and from 68 to 900 ng m-3 in the maintenance work. The exposure of garbage truck drivers to benzo[a]pyrene (B[a]P) ranged from the mean of 0.03 to 0.3 ng m(-3) whereas no B[a]P in control samples or in those collected from maintenance workers was detected. A statistically significant difference in diesel-derived PAH exposure between the garbage truck drivers and the control group in both seasons (in summer p = 0.0022, degrees of freedom (df) 70.5; and in winter p < 0.0001, df = 80.4) was observed. Also, a significant difference in PAH exposure between the garbage truck drivers and the maintenance workers (in summer p < 0.0001, df = 50.1; and in winter p < 0.0001, df = 44.2) was obtained.     

Integrated Nitrogen and Flow Modelling (INCA) in a Boreal River Basin Dominated by Forestry: Scenarios of Environmental Change

A new version (v1.7) of the Integrated Nitrogen in CAtchments model(INCA) was applied to the northern boreal Simojoki river basin (3160 km²) in Finland. The INCA model is a semi-distributed, dynamic nitrogen (N) process model which simulates N transport and processes in catchments. The INCA model was applied to model flow and seasonal inorganic N dynamics of the river Simojoki basin over the period 1994–1996, and validated for two more years. Both calibration and validation of the model were successful. The model was able to simulate annual dynamics of inorganic N concentrations in the river. The effects of forest management and atmospheric deposition on inorganic N fluxes to the sea in 2010 were studied. Three scenarios were applied for forestry practices and two for deposition. The effects of forest cutting scenarios and atmospheric deposition scenarios on inorganic N flux to the sea were small. The combination of the maximum technically possible reduction of N deposition and a decrease of 100% in forest cutting and peat mining areas decreased NO₃ ^--N flux by 6.0% and NH₄ ⁺-N flux by 3.1%.     

利用新一旧冰川沉积物中的类胡萝卜素色素作为波罗的海蓝藻赤潮的标志物

1999年5月从哥特兰海盆、波罗的海本体北部和芬兰湾东部采集到的新-旧冰川沉积物中类胡萝卜素色素的分布情况进行了研究.其目的在于对最近几个世纪以来发生在波罗的海的蓝藻赤潮的发生时间及强度做出+个全面的、系统的、历史性的回顾.色素的存在是利用高压液相色谱(LLC)来检测的,检测的主要重点是把色素作为蓝藻赤潮标志物.从三个采样点采集到的沉积物中的色素的含量有明显差异.总的来说,来自于哥特兰海盆的沉积样中色素的含量最高,而芬兰湾东部样品中的含量最低.在三组沉积样中的最上层(0～lcm)是以β-胡萝卜素为主的胡萝卜素.在岩心样品的深层以蓝藻叶黄素与玉米黄素为主.据我们所知,蓝藻叶黄素和玉米黄素是第一次在波罗的海滨海螺期(Litorina stage)早期的沉积物中被发现.这与沉积物深度相关的色素含量的减少与碳含量的减少是一致的,也和波罗的海蓝藻赤潮发生的强度和时间的历史记录相一致.这一切都表明,第二次世界大战之前在这里很少有蓝藻赤潮发生的记录.     

Effects of phytosterols on zebrafish reproduction in multigeneration test

Zebrafish from mixed sex populations were exposed continuously across three generations to two phytosterol preparations both containing -sitosterol. The phytosterols were isolated from wood and soy beans. Blood vitellogenin levels and sex ratio changes were used as intermediate indicators of the reproduction failures. Both sterol preparations caused vitellogenin induction in the exposed fish. The wood sterol changed the sex ratio of the exposed fish. In generation F1, the predominant sex was male, and in generation F2 it was female. The soy sterol in the used test concentration was lethal to the exposed fish in generation F1. This multigeneration test evidenced that phytosterols containing -sitosterol disrupt the reproduction system of zebrafish by changing the sex ratios and by inducing the vitellogenin production in the exposed fish.