Persistent organic pollutants in a multimedia environment, and associated human health risks: case studies in the region of Campania, Italy, and south-central China

Persistent organic pollutants (POPs) are notoriously toxic chemicals that pose significant threats to human health and ecosystem security. As a result of their volatility and persistence, POPs can be subject to long-range atmospheric transport (LRAT) and, as a result, may be redistributed globally. The harm of POPs to the eco-system is regarded as a global environmental problem, threatening people and animals, which has caused heavy losses economically, ecologically and socially. The environmental problems caused by POPs have finally lead the international community to address the global presence of POPs and reduce their emissions to the environment. Many treaties and laws have been enacted to eliminate or restrict the production and use of some POPs, of which the Stockholm Convention of 2004 on POPs is one of the most famous. Soils are important POPs reservoirs due to their tremendous retention capabilities for these compounds. The huge quantities of POPs accumulated in soils have been an important reemission sources to the atmosphere even after the phasing out of these compounds decades ago. Atmospheric processes are largely responsible for the transport and deposition of polycyclic aromatic hydrocarbons (PAHs), and these compounds may adhere to both atmospheric aerosols and dustfall. Organochlorine pesticides (OCPs) can be easily adsorbed on to suspended particulate matter (SPM) as sediments. SPM can then precipitate in sediments and eventually lower the OCP concentrations in water. Under favorable conditions, sediments can be resuspended, release previously adsorbed OCPs back into the water phase, and initiate another cycle of environmental contamination. So far, the Stockholm Convention has not been ratified by Italy, however, several other regulatory schemes, such as a European Directive in 2000, the UNECE POPs Protocol, and the Rotterdam Convention, are actively followed. The region of Campania falls within the subtropical zone and enjoys a Mediterranean climate. High temperatures in tropical/subtropical regions can facilitate the volatilization and escape of POPs from soils, sediments, and water. The lack of sufficient data on POPs residues, limits the understanding of their health effects, environmental dynamics, and the ultimate fate of these chemicals. China is one of the largest agricultural industries in the world, and was once the largest global producer and consumer of OCPs, especially in the arable southeast region. This Ph.D. thesis presents the results of a series of investigations using a systematic sampling method and geostatistics to illustrate spatial and temporal variations in the concentrations of POPs in different environments, and associated human health risks in Campania, Italy, and south-central China

The occurrence of OCPs, PCBs, and PAHs in the soil, air, and bulk deposition of the Naples metropolitan area, southern Italy: Implications for sources and environmental processes

I am often reminded of the famous saying of Goethe: "Vedi Napoli e poi muori! - See Naples and die!". Sadly, Naples is now confronted with a number of serious, ongoing problems with a need to alleviate pressure on the worsening environment. One serious problem facing the environment is the presence of the potentially hazardous persistent organic pollutants (POPs), although few systematic studies at regional scale have been conducted. In this study, samples of soil, air, and bulk deposition were collected in Naples metropolitan area (NMA) to characterize the status of POPs, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The results obtained showed that most of these compounds are pervasive in all the studied environmental matrices, especially in some hotspot areas, such as the Bagnoli Brownfield Site and the infamous "Triangle of the Death", where unwanted ecological risk conditions for PAHs and Endosulfan were determined, respectively. The interactional complexity between urban and the surrounding rural areas was also confirmed, as is the role that urban areas play in the migration and transformation process of POPs. High urban-rural gradients for atmospheric PAHs and PCBs were observed in the NMA, and the urban areas were identified as the emission source of these contaminants. Similarly, the OCP residues, historically originated from the nearby agricultural regions, experience long-term soil re-emission and continuously influence the connected urban environment via atmospheric transport processes. Keywords: Persistent organic pollutants, Emission sources, Geochemical baseline, Atmospheric transport, Naple

Status, sources and contamination levels of organochlorine pesticide residues in urban and agricultural areas: a preliminary review in central–southern Italian soils

Organochlorine pesticides (OCPs) are synthetic chemicals commonly used in agricultural activities to kill pests and are persistent organic pollutants (POPs). They can be detected in different environmental media, but soil is considered an important reservoir due to its retention capacity. Many different types of OCPs exist, which can have different origins and pathways in the environment. It is therefore important to study their distribution and behaviour in the environment, starting to build a picture of the potential human health risk in different contexts. This study aimed at investigating the regional distribution, possible sources and contamination levels of 24 OCP compounds in urban and rural soils from central and southern Italy. One hundred and forty-eight topsoil samples (0–20 cm top layer) from 78 urban and 70 rural areas in 11 administrative regions were collected and analysed by gas chromatography–electron capture detector (GC–ECD). Total OCP residues in soils ranged from nd (no detected) to 1043 ng/g with a mean of 29.91 ng/g and from nd to 1914 ng/g with a mean of 60.16 ng/g in urban and rural area, respectively. Endosulfan was the prevailing OCP in urban areas, followed by DDTs, Drins, Methoxychlor, HCHs, Chlordane-related compounds and HCB. In rural areas, the order of concentrations was Drins > DDTs > Methoxychlor > Endosulfans > HCHs > Chlordanes > HCB. Diagnostic ratios and robust multivariate analyses revealed that DDT in soils could be related to historical application, whilst (illegal) use of technical DDT or dicofol may still occur in some urban areas. HCH residues could be related to both historical use and recent application, whilst there was evidence that modest (yet significant) application of commercial technical HCH may still be happening in urban areas. Drins and Chlordane compounds appeared to be mostly related to historical application, whilst Endosulfan presented a complex mix of results, indicating mainly historical origin in rural areas as well as potential recent applications on urban areas. Contamination levels were quantified by Soil Quality Index (SoQI), identifying high levels in rural areas of Campania and Apulia, possibly due to the intensive nature of some agricultural practices in those regions (e.g., vineyards and olive plantations). The results from this study (which is in progress in the remaining regions of Italy) will provide an invaluable baseline for OCP distribution in Italy and a powerful argument for follow-up studies in contaminated areas. It is also hoped that similar studies will eventually constitute enough evidence to push towards an institutional response for more adequate regulation as well as a full ratification of the Stockholm Convention

Arsenic in water, sediment, and fish of lakes from the Central Tibetan Plateau

As a potential source of arsenic (As) for the downstream region of the South and East Asia, the As contamination in the Qinghai-Tibet Plateau (QTP) still needs more investigation. In this study, As concentrations in the surface water, lake sediments, and fish of lakes and endorheic rivers in the central Tibet Plateau (CTP) were investigated for the better understanding of As fate in the CTP. Extremely high levels of As in saline lakes water were found with concentrations up to 10,775.40 mu g/L, while the lowest level of As was found in freshwater lakes with a concentration of only 1.80 mu g/L. Natural loading and evaporation concentration were the main reasons for As accumulation in saline lakes in the CTP. Rock weathering and terrestrial ecosystem could affect the As level in the lake. As contents in lake sediments significantly positive related to the As/EC ratios but showed no correlation with As concentrations in the water. Although As levels in the fish were higher in lakes with higher As concentrations, they were still lower than those of the fish from As-contaminated lakes in other studies. Results of this study indicate that hot spots of As in the CTP require more in-depth attention and studies in the future to better understand their influence on the fragile CTP aquatic ecosystem.</p

Distribution, Sources, and Risk Assessment of Organochlorine Pesticides in Water from Beiluo River, Loess Plateau, China

The Loess Plateau has been a focus of public discussion and environmental concerns over the past three decades. In this study, in order to investigate the effect of OCP pollution in water of the Beiluo River, concentrations of 25 OCPs at 17 locations in the water were examined. The results showed that the concentration of ∑OCPs in the water ranged from 1.76 to 32.57 ng L−1, with an average concentration of 7.23 ng L−1. Compared with other basins in China and abroad, the OCP content in the Beiluo River was at a medium level. Hexachlorocyclohexane (HCH) pollution in the Beiluo River was mainly from the mixed input of lindane and technical HCHs. Dichlorodiphenyltrichloroethane (DDT) pollution was mainly from the mixed input of technical DDTs and dicofol. Most of the OCP pollution came from historical residues. The risk assessment results showed that hexachlorobenzene (HCB) and endosulfan had high ecological risks in the middle and lower reaches of the Beiluo River. Most residual OCPs were not sufficient to pose carcinogenic and non-carcinogenic health risks to humans. The results of this study can provide a reference for OCP prevention and control and watershed environmental management

Impacts of ocean current and seabed friction on the picking-up and laying-down processes of oil and gas pipelines

Based on engineering practice of the picking-up and laying-down processes of offshore pipelines, a finite element model was established. On the basis of the model, methods and steps of the picking-up and laying-down operations were determined, and the impacts of currents and seedbed friction on the two operations were studied. The shape and stress distribution of the pipeline under the influences of longitudinal current, lateral current and seabed friction when picked up and laid down were analyzed using finite element analysis software. The results show that the longitudinal current has almost no effect on the pipeline shape and stress distribution in the picking-up and laying-down processes, while the lateral current results in significant deformation of the pipeline in the horizontal plane and raises the overall stress level of the pipeline. The friction between the seabed and the pipeline impedes the lateral displacement of the pipeline when it is laid down. The rougher the seabed, the smaller the overall lateral displacement of the pipeline is. When the pipeline reaches the equilibrium state after it is laid down, the friction between the pipeline and the seabed becomes larger with the increase of the friction coefficient. Key words: finite element model, ocean current, friction coefficient, stress, deformatio

Occurrence, Potential Risk Assessment, and Source Apportionment of Polychlorinated Biphenyls in Water from Beiluo River

Polychlorinated biphenyls (PCBs) are highly hazardous, persistent, and bioaccumulative substances that pose a threat to water quality in a number of locations, including the Beiluo River in Shaanxi Province, China. However, little is known about the contribution of PCBs to the Beiluo River. In this study, in order to look into the impact of sources on the water of the Beiluo River, the discovered PCB congeners in water were examined on a regional scale. The concentration of PCBs in water across Beiluo River was in the range from 0.065 to 1.92 ng L&minus;1, and the average concentration was 0.37 ng L&minus;1. The main PCB sources in the Beiluo River waterbody were found using positive matrix factorization (PMF). Source apportionment results indicated that the PCB pollution of the Beiluo River was mostly caused by industrial emissions, technical PCB mixtures, and coal and wood combustion. According to current ecological risk assessment guidelines, the PCB concentrations found in this study may have a negative impact on biological systems. Overall, the new information about the presence of several PCBs in the water of the Beiluo River justifies the need for urgent management actions, as well as long-term monitoring efforts, to protect ecosystems. Future investigations of these chemicals in China may use the conclusions of this first ecological risk level assessment on the PCB contamination in the waterbody of the Beiluo River as a guide

Distribution, Sources and Risk Assessment of Polychlorinated Biphenyls in Sediments from Beiluo River

The distribution and source of polychlorinated biphenyls (PCBs) pollution in the Beiluo River, the secondary tributary of the Yellow River, still remain unclear. With the purpose of determining the distribution, origins, and pollution levels of PCBs and their consequences on ecological risks, the concentrations of 27 PCBs at 17 locations in the sediments of the Beiluo River were examined in this study. The results showed that the mass concentrations of &sum;PCBs in the sediment ranged from 0.12 to 1.25 ng&#8729;g&minus;1 (DW), with the highest point at sampling site B13 downstream of the river. Compared to most river sediments, both domestically and internationally, the concentration of PCBs in the sediment of the Beiluo River was at a low level, with 10-PCB and 6-PCB as the main components, indicating that the PCBs that are difficult to volatilise and degrade are more likely to remain in the sediment. The origins of PCBs in the sediments of the Beiluo River were examined by using positive matrix factorisation (PMF). The results revealed that the contamination of PCBs in the sediments of the Beiluo River mainly resulted from industrial emissions, technical PCB mixtures, and coal and wood combustion. The results of the ecological risk assessment indicated that PCBs in the sediments of the study area rarely contribute to adverse biological effects and the potential low risk to the environment