Marine litter pollution has become a complex global problem, because of the negative ecological and socioeconomic impacts as well as the human health risks that it represents. In Colombia, mangroves are affected by inadequate solid waste management, which results in litter accumulation. Additionally, the information related to this problem is limited avoiding the development of prevention and reduction strategies. For the first time, pollution by marine litter and microplastics were evaluated in mangrove soils of the Ciénaga Grande de Santa Marta, where 540 ± 137 and 31 ± 23 items/ha of marine litter were determined in mangroves near and away from populated centers respectively. Plastics represented between 73 and 96% of litter, and microplastic quantity oscillated between 31 and 2,863 items/kg finding the highest concentrations in mangroves near to the population. This study contributes to the knowledge of the marine litter problem in mangroves of the Colombian Caribbean, becoming a help for their conservation.

Coastal urbanization is leading to the accumulation of anthropogenic litter. Understanding the distribution and habitat use of litter by marine biota is important to predict how organisms will respond to anthropogenic changes. We assessed the density, distribution and composition of surface macro-litter (SML) in mangrove forests in Buenaventura (Colombia) and analysed how these microhabitats are used by marine biota. SML density ranged from 2 to 314 g m⁻² (0.22 to 35.5 items m⁻²), implying that mangrove forests surrounding Buenaventura city are among the most polluted coastal areas in the World. Biological assemblages colonizing SML differed according to position on the forest and litter type. The encroachment of SML in mangrove forest enables a seemingly transient colonization of resident and immigrant biota from intertidal rocky shores and subtidal hard bottoms. The successful colonization of SML poses questions regarding the potential for plastics or their leaching chemicals to transfer through food webs.

Sources of organic matter in a polluted coastal embayment (Lake Sihwa) indicated that δ¹³C and δ¹⁵N of suspended particulate matter (SPM) and sediments could be distinguished by land-use type and surrounding activities. Specifically, low δ¹⁵N occurred in inland creeks near industrial complex, where severe contamination by persistent toxic substances (PTSs) is evidenced. To identify the sources of ¹⁵N-depleted organic matter and PTSs, the SPM and/or sediments were collected along ~8 km of the Singil Creek and in stormwater drainage pipes that carried pollutants to the creeks from upland areas. Results indicated that stormwater originating in industrial areas was the main source of low δ¹⁵N and elevated PTSs, which appeared to flow into stormwater drains with rainwater and eventually into the creeks at stormwater outfalls. To improve the water quality of inland creeks, it will be necessary to reduce the amount of untreated stormwater entering stormwater drainage system from industrial complex.

The Water Framework Directive (WFD) currently supports chemical and ecological monitoring programmes in order to achieve the good water surface status. Although chemical and ecological assessments are necessary, they have some limitations. Chemical approaches focus on certain substances identified as priorities, but they do not take into account other potentially harmful substances and also ignore the hazards related to contaminant cocktails. On the other hand, while ecological approaches provide holistic information on the impairment of biological communities in ecosystems, they do not distinguish the role of contaminants in these alterations, and consequently do not allow the establishment of contaminant impact reduction plans. Consequently, ecotoxicologists suggest the use of effect-based tools such as biomarkers. Biomarkers highlight the effect of potentially harmful substances (or a cocktail), and their specificity towards the chemicals makes it possible to properly discriminate the role of toxicants within biological community impairments. Thus, the integration of such tools (besides existing chemical and ecological tools) in the WFD could considerably improve its biomonitoring strategy. The B n' B project (Biomarkers and Biodiversity) exposes key objectives that will allow to (i) establish an inventory of the biomarkers developed by French laboratories; (ii) determine their methodological advancement and limits and, on this basis, formulate recommendations for biomonitoring use and future research needs; (iii) discuss the biomarkers' ecological significance, specificity to contaminants and interpretation capacity; (iv) establish, in fine, a selection of valuable biomarkers to enter the WFD; and (iv) propose integrative tools to facilitate the decision-taking by stakeholders.

A study of pesticides in the Bizerte lagoon watershed on the Mediterranean coast of Tunisia showed that herbicides and fungicides are the most commonly used compounds. A survey was made of selected farmers. Pesticide contamination was monitored in the water column and sediments at four selected sampling sites (lagoon (A) and in three ouedsChegui (B), Garaa (C), and Tinja (D)). Polar organic chemical integrative samplers (POCIS) were used to assess pesticide contamination. Thirty-two pesticides were investigated; the total concentration of active ingredients ranged from 35.9ngL(-1) in Tinja oued to 1246ngL(-1) in Chegui oued. In the lagoon, the total concentration of pesticides was 67.7ngL(-1). In the sediments, the highest concentration was measured in Chegui oued in the spring (31ngg(-1) dw). The main compounds found in the analyzed sediments were prosulfocarb and tebuconazole molecules.

The air quality is an increasingly concerning topic. Efficient air quality monitoring system is highly required in urban areas due to the existing different types of air pollution sources. Consequently, air pollution profiles of the monitored region should be regularly evaluated to infer the efficiency of the monitoring system. This study applied principal components analysis (PCA) to air quality data from Porto (Portugal), aiming to characterize the spatial distribution of NO₂, O₃ and PM₁₀ concentration profiles. In the analysed period (2006 and 2013), some of the selected monitoring sites have been closed and others were moved to other locations. PCA allowed the evaluation of these changes in geographical distribution of the monitoring sites and the definition of proposals to improve the efficiency of air quality monitoring system. The performed analysis concluded that these last changes were correctly performed, but the reduction of the monitoring sites for NO₂ and O₃is still possible, being optimized the current number for PM₁₀. In addition, the application of computational model HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) allowed analysing the air pollution transport over long distances in high pollutant concentration episodes, having found that the variation of NO₂ and O₃ concentrations may be strongly influenced by air masses from the north of Spain. For PM₁₀, there are two different air mass trajectories: the transport of air masses from the Galicia region and from North Africa.

The air-water exchange of polycyclic aromatic hydrocarbons (PAHs) is an important process in determining the fate, transport and chemical loadings of these contaminants in the atmosphere and water bodies. Concentration levels of PAHs in air (gaseous and particulate) and surface water were investigated in the environments of two polluted lagoons along the eastern coast of the Red Sea to study air water exchange and dry deposition fluxes. Nine priority parent PAHs and nine methylated PAHs were identified and quantified by GC-MS. The range of total PAHs in surface water was from 120.29 ng L⁻¹ to 524.45 ng L⁻¹ (average: 308.7 ng L⁻¹, n = 19). The PAHs levels in air recorded significant rise form the previous study. The probable sources of dissolved PAHs in water were found predominantly to be of petrogenic origin in one lagoon and of pyrogenic origin in the other lagoon. The dry deposition fluxes for individual congeners ranged between 0.01 ng m⁻²d⁻¹ to 2.82 μg m⁻²d⁻¹. After Henry's law constant corrections for temperature and salinity; the air-water exchange fluxes were found in the range of −9.7 × 10⁴ to 8.6 × 10⁶ ngm⁻²d⁻¹ with an average of 6.8 × 10⁵ ngm⁻²d⁻¹. Beside the other sources of PAHs in the studied lagoons, high temperature and wastewater dumping might affect the magnitude and direction of air-water exchange fluxes.

The aim of this study was to assess if the epiphyte Tillandsia bergeri is feasible to be used as a biomonitor of pesticides in the air by comparing with the results of the artificial XAD-resin based passive air sampler (XAD-PAS). Biomonitors and XAD-PAS were deployed at 10 sites of Quequén Grande River watershed (Buenos Aires province, Argentina) during three exposure periods. Endosulfan was the main pesticide found in T. bergeri as well as in XAD-PAS, even after the ban was in effect. Higher endosulfan levels were observed during pesticide application period in XAD-PAS, while T. bergeri showed a decreasing trend during this period. Chlorpyrifos concentrations were in the same order than endosulfan in XAD-PAS, while T. bergeri showed significantly lower levels. Concentrations of legacy pesticides (hexachlorocyclohexanes, chlordanes, dieldrin, heptachlors) registered a low contribution to total pesticides analyzed both in T. bergeri and XAD-PAS, reflecting the past use of organochlorine pesticides in the region. Trifluralin showed the lowest concentrations in T. bergeri while XAD-PAS exhibited a higher proportion in some sites. Even both samplers showed that endosulfan was the most frequent pesticide found, environmental processes such as volatilization and photodegradation, as well as biological processes in T. bergeri have probably occurred and therefore pesticides accumulation was altered. Results demonstrate the importance of taking into account the type of sampling media when analyzing atmospheric pesticide composition. Nevertheless, the use of T. bergeri and XAD-PAS allowed discriminating efficiently the relative contribution of currently used pesticides versus legacy pesticides to air pollution.