Organic pollutants in microplastics from two beaches of the Portuguese coast

Microplastics pose a threat to coastal environments due to their capacity to adsorb persistent organic pollutants (POPs). These particles (less than 5 mm in size) are potentially dangerous to marine species due to magnification risk over the food chain. Samples were collected from two Portuguese beaches and sorted in four classes to relate the adsorption capacity of pollutants with color and age. Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and DDTs were analysed on pellets through gas chromatography mass spectrometry (GC-MS), and types of plastic were identified using Fourier transformed infra-red spectroscopy (micro-FTIR). Microplastics were mostly polyethylene and polypropylene. Regarding sizes, some fibres ranged from 1 to 5 μm in diameter and were 500 μm in length. The majority of samples collected had sizes above 200 μm. Black pellets, unlike aged pellets, had the highest concentrations of POPs except for PAHs in Fonte da Telha beach. PAHs with higher concentrations were pyrene, phenantrene, chrysene and fluoranthene. Higher concentrations of PCBs were found for congeners 18, 31, 138 and 187. Further investigation is necessary to understand the relationship between plastic degradation and adsorption for different pollutants.     

International Pellet Watch: Global monitoring of persistent organic pollutants (POPs) in coastal waters. 1. Initial phase data on PCBs, DDTs, and HCHs

Samples of polyethylene pellets were collected at 30 beaches from 17 countries and analyzed for organochlorine compounds. PCB concentrations in the pellets were highest on US coasts, followed by western Europe and Japan, and were lower in tropical Asia, southern Africa and Australia. This spatial pattern reflected regional differences in the usage of PCBs and was positively correlated with data from Mussel Watch, another monitoring approach. DDTs showed high concentrations on the US west coast and in Vietnam. In Vietnam, DDT was predominant over its metabolites (DDE and DDD), suggesting the principal source may be current usage of the pesticide for malaria control. High concentrations of pesticide HCHs were detected in the pellets from southern Africa, suggesting current usage of the pesticides in southern Africa. This study demonstrates the utility and feasibility of the International Pellet Watch approach to monitor POPs at a global scale.     

Diffuse pollution by persistent organic pollutants as measured in plastic pellets sampled from various beaches in Greece

Plastic pellets found stranded on beaches are hydrophobic organic materials and thus, they are a favourable medium for persistent organic pollutants to absorb to. In the present study, plastic pellets are used to determine the diffuse pollution of selected Greek beaches. Samples of pellets were taken from these beaches and were analyzed for PCBs, DDTs, HCHs, and PAHs. The observed differences among pellets from various sampling sites are related to the pollution occurring at each site. Plastic pellets collected in Saronikos Gulf beaches demonstrate much higher pollutant loading than the ones collected in a remote island or close to an agricultural area. Based on data collected in this study and the International Pellet Watch program, pollution in Saronikos Gulf, Greece, is comparable to other heavily industrialized places of the world. The present study demonstrates the potential of pellet watch to be utilized as a detailed-scale monitoring tool within a single country.     

Occurrence, distribution and characteristics of beached plastic production pellets on the island of Malta (central Mediterranean)

The distribution, abundance and chemical characteristics of plastic production pellets on beaches of the island of Malta have been determined. Pellets were observed at all locations visited and were generally most abundant (>1000 m⁻² at the surface) on the backshores of beaches with a westerly aspect. Most pellets were disc-shaped or flattened cylinders and could be categorised as white, yellow, amber or brown. The polymeric matrix of all pellets analysed by infrared spectroscopy was polyethylene and the degree of yellowing or darkening was associated with an increase in the carbonyl index, hence extent of photo-oxidation or aging. Qualitatively, pellets are similar to those reported for other regions of the Mediterranean in surveys spanning three decades, suggesting that they are a general and persistent characteristic of the region.     

Quantitative analysis of small-plastic debris on beaches in the Hawaiian Archipelago

Small-plastic beach debris from nine coastal locations throughout the Hawaiian Archipelago was analyzed. At each beach, replicate 20 l samples of sediment were collected, sieved for debris between 1 and 15 mm in size, sorted by type, counted and weighed. Small-plastic debris occurred on all of the beaches, but the greatest quantity was found at three of the most remote beaches on Midway Atoll and Moloka'i. Of the debris analyzed, 72% by weight was plastic. A total of 19100 pieces of plastic were collected from the nine beaches, 11% of which was pre-production plastic pellets. This study documents for the first time the presence of small-plastic debris on Hawaiian beaches and corroborates estimates of the abundance of plastics in the marine environment in the North Pacific.     

Composition and distribution of beach debris in Orange County, California

Many studies have quantified debris collected on beaches around the world. Only a few of those studies have been conducted in the United States, and they are largely limited to semi-quantitative efforts performed as part of volunteer clean-up activities. This study quantifies the distribution and composition of beach debris by sampling 43 stratified random sites on the Orange County, California coast, from August to September 1998. We estimated that approximately 106 million items, weighing 12 metric tons, occur on Orange County beaches. The most abundant items were pre-production plastic pellets, foamed plastics, and hard plastics. Debris density on the remote rocky shoreline was greater than that on high-use sandy beaches for most debris items. This finding partially reflects the periodic clean-up of high-use beaches by local municipalities, and also indicates that a high percentage of the observed debris was transported to the site from waterborne sources.     

Concentration of polychlorinated biphenyls (PCBs) in beached resin pellets: variability among individual particles and regional differences

Concentrations of polychlorinated biphenyls (PCBs) in beached resin pellets were examined to reveal variability between individual particles and differences among beaches. Fifty-five resin pellets from a beach in Tokyo were individually analyzed for PCBs, and showed concentrations ranging from <28 to 2,300 ng/g. This indicates that concentrations are highly variable between particles. Among several characters, discoloration (e.g., yellowing) had a positive relationship with PCB concentration: discolored pellets contained more PCBs than others on most of the beaches sampled. Given the color-selective ingestion of food by some organisms, this may be ecotoxicologically important. Measurements of samples from 47 beaches in Japan showed regional differences in PCB concentrations in resin pellets consistent with those in mussels. Sporadic high concentrations of PCBs were also found in pellets from remote islands, suggesting that resin pellets could be the dominant route of exposure to the contaminants at remote sites. The similarity of PCB concentrations between resin pellets and mussels suggests a potential use of resin pellets to monitor pollution in seawater.     

Plastic pellets and tar on Spain's Mediterranean beaches

Eighteen beaches on the Mediterranean coast of Spain, from Barcelona to Algeciras, were surveyed for the presence of plastic pellets. Spherules in great variety of shape and colour, often covered with tar, were found to be abundant on most beaches, particularly at Sitges, Calafell, and Salou on the Costa Dorada and Gandia on the Costa del Azahar. Tar lumps were also very common.Over 100 of Spain's approximately 190 plastics manufactures are situated on or near the Mediterranean coast. Wastes from these factories and spillage during cargo loading and sea transport of raw materials are thought to be the most likely major sources of the pellets.It is further suggested that, due to the regular raking and cleaning of the beaches before and during the tourist season, many pellets are buried or ‘cleaned’ away, and plastic pellets may therefore occur much more abundantly on Spain's beaches than has thus far been observed.     

Association of metals with plastic production pellets in the marine environment

Plastic production pellets sampled from four beaches along a stretch of coastline (south Devon, SW England) and accompanying, loosely adhered and entrapped material removed ultrasonically have been analysed for major metals (Al, Fe, Mn) and trace metals (Cu, Zn, Pb, Ag, Cd, Co, Cr, Mo, Sb, Sn, U) following acid digestion. In most cases, metal concentrations in composite pellet samples from each site were less than but within an order of magnitude of corresponding concentrations in the pooled extraneous materials. However, normalisation of data with respect to Al revealed enrichment of Cd and Pb in plastic pellets at two sites. These observations are not wholly due to the association of pellets with fine material that is resistant to ultrasonication since new polyethylene pellets suspended in a harbour for 8 weeks accumulated metals from sea water through adsorption and precipitation. The environmental implications and potential applications of these findings are discussed.     

International survey on the distribution of stranded and buried litter on beaches along the Sea of Japan

The distribution and abundance of marine litter on 26 beaches along the Sea of Japan were investigated from September to November 2000. The mean concentration of stranded litter in Japan and Russia was 2144 and 1344 g/100 m(2), respectively. The mean number of pieces of stranded litter in Japan and Russia was 341 and 20.7/100 m(2), respectively. The most abundant type of stranded litter was plastic, which accounted for 40-80 % of the total items in terms of weight and number. The mean concentration of buried litter in Japan and Russia was 9.03 and 2.70 g/m(2), respectively. The total weight ratio of buried litter to stranded litter in the samples was 0.65, suggesting the significance of buried litter when evaluating the status of litter on beaches. Resin pellets were found on 12 Japanese beaches, but on none of the Russian beaches.     

Shore litter along sandy beaches of the Gulf of Oman

Beach debris abundance and weight were estimated from surveys on 11 beaches of the Gulf of Oman along the Omani coast. Debris were collected on two occasions from 100 m transects, sorted and categorized by origin and type. Overall contaminations ranged from 0.43 to 6.01 items m(-1) of beach front on different beaches with a mean value of 1.79+/-1.04 gm(-1) (95% C.I). In terms of weight, contamination levels ranged from 7.8 to 75.44 gm(-1) of beach front with a mean contamination of 27.02+/-14.48 gm(-1) (95% C.I). In terms of numbers of items, plastic debris ranked first on all beaches followed by either wood items or other organic materials such as cigarette butts. Industrial debris remained few on all beaches (<10%). Most debris had a local origin and, in terms of numbers, were associated with beach recreational activities whereas fishing debris represented the largest proportion of the debris in terms of weight. There were notable differences between beaches in the relative abundance of recreation-related and fishing-related debris.     

Plastic pellets on the coast of Lebanon

The occurrence of plastic pellets along the coast of Lebanon is being reported for the first time. Although a variety of colours, shapes, and sizes was observed, most pellets seemed to be either an opaque-white or transparentamber colour, cylindrical to oval or round, and 2–5 mm in diameter. A random sampling was taken and the results of thermal analysis showed the pellets to be of either high density polyethylene (opaque-white pellets), polymethyl methacrylate (transparent), or polystyrene (amber).The presence of these pellets is most likely due to waste disposal by the numerous plastics ‘factories’ in the country, or possibly, cargo-loss during sea transport of raw plastics materials.     

Bather density as a predominant factor for health effects related to recreational bathing: results from the Greek bathers cohort study

Our aim was to examine the health effects on bathers from exposure to recreational seawater on three beaches with different microbiology quality and bather density through a cohort study. An initial questionnaire and a 10 day follow up were used. Univariate and backward logistic regression analyses were used to asses the risk of developing symptoms or diseases among the bathers. In total, 3805 bathers were included in the study and 149 samples were collected from the three beaches. Despite all the beaches being characterized of high quality the levels of bacterial indicators differed among them. Health effects among bathers were not associated with bacterial indicators. A statistically significant increased risk for symptoms related to respiratory illness, gastroenteritis, medical consultation and use of medication was observed among bathers at the higher bather density beaches. Beach bather numbers should always be taken into account when considering a risk assessment approach.     

Application of food waste based diets in polyculture of low trophic level fish: Effects on fish growth,water quality and plankton density

Food waste was collected from local hotels and fish feed pellets were produced for a 6 months long field feeding trial. Three types of fish feed pellets (control diet: Jinfeng® 613 formulated feed, contains mainly fish meal, plant product and fish oil; Diet A: food waste based diet without meat and 53% cereal; Diet B: food waste based diet with 25% meat and 28% cereal) were used in polyculture fish ponds to investigate the growth of fish (grass carp, bighead and mud carp), changes in water quality and plankton density. No significant differences in the levels of nitrogen and phosphorous compounds of water body were observed between 3 fish ponds after the half-year feeding trial, while pond receiving Diet A had the highest density of plankton. The food waste combination of Diet B seems to be a better formulation in terms of the overall performance on fish growth.     

Monitoring of organic micropollutants in Ghana by combination of pellet watch with sediment analysis: E-waste as a source of PCBs

Plastic resin pellets collected at 11 beaches covering the whole Ghanaian coastline were analyzed for polychlorinated biphenyls (PCBs). PCB concentrations (∑13 congeners) were higher in Accra, capital city, and Tema (39–69 ng/g-pellets) than those in rural coastal towns (1–15 ng/g-pellets) which are close to global background, indicating local inputs of PCBs. River sediments were also analyzed for PCBs together with molecular markers. Sedimentary PCBs concentrations were highest at a site (AR02) downstream of an electronic waste (e-waste) scrapyard. At the site (AR02), concentration of linear alkylbenzenes (LABs), a marker of municipal wastewater, was lower than another site (AR03) which is located at the downstream of downtown Accra. This result suggests that PCBs are introduced more to the river from the e-waste site than from activities in downtown Accra. PAHs concentrations were relatively higher in urban areas with strong petrogenic signature. Abundance of triphenylbenzenes suggested plastic combustion near e-waste scrapyard.     

Plastic pellets as oviposition site and means of dispersal for the ocean-skater insect Halobates

Microplastics are omnipresent in the oceans and generally have negative impacts on the biota. However, flotsam may increase the availability of hard substrates, which are considered a limiting resource for some oceanic species, e.g. as oviposition sites for the ocean insect Halobates. This study describes the use of plastic pellets as an oviposition site for Halobates micans and discusses possible effects on its abundance and dispersion. Inspection of egg masses on stranded particles on beaches revealed that a mean of 24% (from 0% to 62%) of the pellets bore eggs (mean of 5 and max. of 48 eggs per pellet). Most eggs (63%) contained embryos, while 37% were empty egg shells. This shows that even small plastic particles are used as oviposition site by H. micans, and that marine litter may have a positive effect over the abundance and dispersion of this species.     

Desorption kinetics of hydrophobic organic contaminants from marine plastic pellets

This study investigated the desorption behavior of polychlorinated biphenyls (PCBs) from marine plastic pellets. Long-term desorption experiments were conducted using field-collected polyethylene (PE) pellets. The results indicate that the desorption kinetics highly depends on the PE-water partition coefficients of PCB congeners. After 128 d of the experiment, the smallest congener considered (CB 8) had desorbed nearly completely (98%), whereas major fractions (90–99%) of highly chlorinated congeners remained in the pellets. An intraparticle diffusion model mostly failed to reproduce the desorption kinetics, whereas an aqueous boundary layer (ABL) diffusion model well approximated the data. The desorption half-lives are estimated to 14 d to 210 years for CB 8 to CB 209 in an actively stirred solution (ABL thickness: 30 μm). Addition of methanol to water enhanced the desorption to a large extent. A need for further work to explore roles of organic matter in facilitating solute transfer is suggested.     

Small plastic debris changes water movement and heat transfer through beach sediments

We investigated the physical properties of beaches contaminated with plastic fragments. We compared sediment cores from Hawai‘i Island’s Kamilo Beach, notable for plastic accumulation, to cores from a nearby beach. Compared to the nearby beach, Kamilo sediments contained more plastics (up to 30.2% by weight), were coarser-grained, and were more permeable (t-test, p < 0.0001). 85% of the fragments were polyethylene, and 95% were concentrated in the top 15 cm of the cores. We constructed artificial cores of standardized grain size and varying plastic-to-sediment ratios. Adding plastic significantly increased the permeability (ANOVA, p = 0.002), which was partially attributed to the fragments increasing the mean grain size. Sediments with plastic warmed more slowly (16% maximum decrease in thermal diffusivity), and reached lower maximum temperatures (21% maximum increase in heat capacity). These changes have a variety of potential effects on beach organisms, including those with temperature-dependent sex-determination such as sea turtle eggs.     

Long-term decreases in persistent organic pollutants in South African coastal waters detected from beached polyethylene pellets

Polyethylene pellets provide a convenient means to monitor Persistent Organic Pollutants (POPs) in marine systems. Pellets collected between 1984 and 2008 at three South African beaches were analysed for PCB, HCH and DDT. Concentrations of all three POPs decreased over the last two decades, although this signal was less clear for PCBs, and further monitoring is needed to assess trends in this family of compounds. DDT concentrations at two sites were higher than previous records for southern Africa, but there is no evidence of a link to the ongoing use of DDT for malaria control. HCHs concentrations were lower than in pellets from the east coast of southern Africa, suggesting that this pesticide was mainly used in the eastern part of the region. Our study demonstrates the potential for International Pellet Watch to track temporal as well as geographical patterns in the abundance of POPs in marine environments.     

Oregon Beach Monitoring Program: Bacterial exceedances in marine and freshwater creeks/outfall samples, October 2002-April 2005

A total of 3086 samples, both marine (2916) and freshwater creeks/outfall samples (170) were collected and analyzed for enterococci during October 2002-April 2005, from 52 designated beaches in Oregon. A total of 3.2% (99/3086) of the samples at 21 beaches exceeded 158 most probable number (MPN)/100 milliliters (mL). The average enterococci levels of these 99 exceedances was 559 MPN/100 mL, with a maximum of 4352 MPN/100 mL (Otter Rock and Ona) and a minimum of 160 MPN/100 mL (Sunset Bay State Park, Bastendorff, and Mill). For marine water, 77/2916 (2.6%) exceeded 158 MPN/100 mL. For freshwater, 22/170 (12.9%) exceeded 158 MPN/100 mL, with a maximum of 587 MPN/100 mL at Sunset Bay. Sixty percent of the marine and 9% of freshwater exceedances occurred during the winter. Seventy-two percent (55/77) of the marine exceedances occurred after rainfall events (0.01-60.0 mm). At Harris and Mill Beaches, cumulative rainfall was highly correlated with bacterial densities, R = 0.7. Rainfall, at both beaches, explained about one-half the variation in log10 bacteria density (R2 = 0.5). Additional monitoring is warranted to further characterize bacterial contamination in Oregon waters.