Intensive urbanisation of the Croatian capital of Zagreb has led to a situation where very good agricultural soils, developed mostly on Pleistocene eolian sediments and alluvial and proluvian Holocene sediments are entrapped within urban and suburban areas. Therefore the influence of urban and industrialised environments on the accumulation of metals in agricultural topsoils has been investigated. On an area of 860 km 2 of the wider Zagreb region, 331 samples were taken according to a regular 1·1 km square mesh. Samples were dissolved in aqua regia and analysed for Cd, Cu, Fe, Mn, Ni, Pb and Zn with flame atomic aqua regia absorption spectroscopy. The following concentration ranges have been determined: Cd 0.25-3.85 mg kg -1 (average 0.66 mg kg -1 ), Cu 4.30-183 mg kg -1 (average 20.8 mg kg -1 ), Fe 5.8-51.8 g kg -1 (average 27 g kg -1 ), Mn 79.2-1282 mg kg -1 (average 613 mg kg -1 ), Ni 0.70-282 mg kg -1 (average 49.5 mg kg -1 ), Pb 1.50-139 mg kg -1 (average 25.9 mg kg -1 ), and Zn 15.2-277 mg kg -1 (average 77.9 mg kg -1 ). Visualisation of the spatial data is made by the aid of GIS, and selected maps of the heavy metal concentrations in topsoils are displayed. Statistical multivariate analysis was carried out for quantitative study and data were processed by means of R-mode factor analysis, applying the varimax-raw rotational technique. F1, which grouped Cd, Pb, Cu, Zn and partially Ni, is characterized as a factor with strongly scattered anthropogenic influence. The elements in F2, Fe, Mn and partially Ni are mainly of geogenic, i.e. pedogenic, origin. The variations in concentrations of the investigated elements are thus of both natural and anthropogenic origins. The variations in the main soil constituents, particularly Fe and Mn, are determined primarily by the composition of different regolithic substrates of the fluvial origin in recent pedogenesis. High concentrations of nickel are also related to morphogenetic characteristics of the wider region, primarily basic and ultrabasic magmatic rocks of the surrounding mountain range. It is, however, assumed that the anomalous nickel concentrations in the vicinity of the highway and the airport are of anthropogenic origin, i.e. caused by fuel combustion. Copper is characterized by strongly scattered anthropogenic influence, which is related particularly to uncontrolled solid waste disposals or discharges of liquid waste from households or agricultural enterprises. With Zn, Pb and Cd, there are two possible ways of diffuse pollution. The Sava River, which drains the area and feeds the abundant Quaternary aquifer spreading below the major part of the investigated agricultural areas, has been exposed to intensive pollution by mining, industry and cities in the recent history. The part of the area with the highest determined concentrations of Zn, Pb and Cd was repeatedly flooded as recently as the previous decade; therefore, the recent sedimentation of the river deposits exposed to pollution is a very probable cause of the accumulation of metals in this until rece...

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Trace metals accumulation in soil irrigated with polluted water and human health risk from vegetable consumption was assessed based on the data available in the literature on metals pollution of water, soil, sediment and vegetables from the cites of Bangladesh. The quantitative data on metal concentrations, their contamination levels and their pollution sources have not been systematically gathered and studied so far. The data on metal concentrations, sources, contamination levels, sample collection and analytical tools used were collected, compared and discussed. The USEPA-recommended method for health risk assessment was used to estimate human risk from vegetable consumption. Concentrations of metals in water were highly variable, and the mean concentrations of Cd, Cr, Cu and As in water were found to be higher than the FAO irrigation water quality standard. In most cases, mean concentrations of metals in soil were higher than the Bangladesh background value. Based on geoaccumulation index (I ) values, soils of Dhaka city are considered as highly contaminated. The I shows Cd, As, Cu, Ni, Pb and Cr contamination of agricultural soils and sediments of the cities all over the Bangladesh. Polluted water irrigation and agrochemicals are identified as dominant sources of metals in agricultural soils. Vegetable contamination by metals poses both non-carcinogenic and carcinogenic risks to the public. Based on the results of the pollution and health risk assessments, Cd, As, Cr, Cu, Pb and Ni are identified as the priority control metals and the Dhaka city is recommended as the priority control city. This study provides quantitative evidence demonstrating the critical need for strengthened wastewater discharge regulations in order to protect residents from heavy metal discharges into the environment.

A 2-year study was conducted in the Vrana Valley (Mediterranean region of Croatia) to evaluate the effects of application of different mulching materials and drip-fertigation on nitrate leaching in bell pepper (Capsicum annuum L.) cultivation. Nitrate-N leaching from the root zone of bell pepper was compared in three treatments: control without mulch, with black polyethylene (PE) mulch and with biodegradable cellulose mulch. In the first year, the highest quantities of nitrogen were leached in the treatment without mulch (26 kg ha À1 ) following by the treatment with cellulose mulch (18 kg ha À1 ) and the lowest nitrogen leaching (10 kg ha À1 ) was observed in the treatment with black PE mulch. At the end of the harvest, cellulose mulch, a microbiologically degradable material, started to decompose and disintegrate, which resulted in the cellulose mulch treatment behaving similarly than the control treatment without mulch. In the second year, significant leaching occurred after the last harvest in September. As the bell pepper yield was significantly lower than expected and calculated for fertilisation, the crop did not take up all nitrogen supplied by fertilisation, which resulted in higher concentrations of nitrate in the soil solution. These nitrate concentrations were subjected to leaching caused by precipitation, a regular occurrence in the autumn and winter in this region. However, mulched surfaces showed lower quantities of nitrate leached in comparison with the treatment without mulching. Mulching with black PE film, besides producing higher yields, reduces the leaching of nitrate fertilisers, and combined with fertigation can reduce a potential risk of surface and ground water pollution by nitrate. #