Recent studies have demonstrated the negative impacts of microplastics on wildlife. Therefore, the presence of microplastics in marine species for human consumption and the high intake of seafood ...(fish and shellfish) in some countries cause concern about the potential effects of microplastics on human health. In this brief review, the evidence of seafood contamination by microplastics is reviewed, and the potential consequences of the presence of microplastics in the marine environment for human food security, food safety and health are discussed. Furthermore, challenges and gaps in knowledge are identified. The knowledge on the adverse effects on human health due to the consumption of marine organisms containing microplastics is very limited, difficult to assess and still controversial. Thus, assessment of the risk posed to humans is challenging. Research is urgently needed, especially regarding the potential exposure and associated health risk to micro- and nano-sized plastics.
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•Marine microplastic debris may compromise human food security, food safety and health.•Microplastics have been detected in commercial sea food and other food items and drinking water.•Research on analytical methods, toxicity and toxicokinetics in humans of micro- and nano-sized plastics is needed.•Our knowledge in this field is still far from complete.
•EC50 procainamide growth rate/chlorophyll (mg/l): 104/143 (alone).•EC50 procainamide growth rate/chlorophyll (mg/l): 125/31 (with microplastics).•EC50 doxycycline growth rate/chlorophyll (mg/l): ...39/24 (alone).•EC50 doxycycline growth rate/chlorophyll (mg/l): 21/13 (with microplastics).•Microplastics presence increased pharmaceuticals toxicity.
Microplastics and pharmaceuticals are considered ubiquitous and emergent pollutants of high concern but the knowledge on their effects on primary producers is still limited, especially those caused by mixtures. Thus, the goal of the present study was to investigate if the presence of microplastics (1–5 μm diameter) influences the toxicity of the pharmaceuticals procainamide and doxycycline to the marine microalga Tetraselmis chuii. Bioassays (96 h) to investigate the toxicity of those substances individually and in mixtures (i.e. microplastics-procainamide mixtures and microplastics-doxycycline mixtures) were carried out. Effect criteria were the average specific growth rate (growth rate) and chlorophyll a concentration (chlorophyll). EC10, EC20 and EC50 were determined. Microplastics alone had no significant effects on growth rate up to 41.5 mg/l, whereas chlorophyll was significantly reduced at 0.9 and 2.1 mg/l of microplastics, but not at higher concentrations. The 96 h EC50 (growth rate and chlorophyll, respectively) determined for the other bioassays were: 104 and 143 mg/l for procainamide alone; 125 and 31 mg/l for procainamide in the presence of microplastics; 22 and 14 mg/l for doxycycline alone; 11 and 7 mg/l for doxycycline in the presence of microplastics. Significant differences (p < 0.001) between the toxicity curves of each pharmaceutical alone and in mixture with microplastics were found for procainamide (chlorophyll), and doxycycline (both parameters). Thus, both pharmaceuticals were toxic to T. chuii in the low ppm range, and microplastics-pharmaceutical mixtures were more toxic than the pharmaceuticals alone. Very high decreases of doxycycline concentrations in test media were found, indicating degradation of the antibiotic. Thus, although the biological results are expressed in relation to doxycycline concentration, the effects were likely caused by a mixture of the parental compound and its degradation products. The concentrations of microplastics and pharmaceuticals tested (low ppm range) are higher than those expected to be found in waters of the most part of marine ecosystems (ppt or ppb ranges). However, considering the widespread contamination by microplastics and pharmaceuticals, the concentrations already found in waters, sediments and/or organism of heavily polluted areas, the long-term exposure (over generations) of wild populations to such substances in polluted ecosystems and the possibilities of bioaccumulation and toxicological interactions, these findings are of concern and further research on microplastics-pharmaceuticals toxicological interactions is needed.
Copepods are largely used in toxicity tests. The nauplii of these organisms are more sensitive to contaminants than the adult stage. The aim of the present study was to test a protocol for the use of ...nauplii of the copepod Tisbe biminiensis in the ecotoxicological assessment of seawater. The sensitivity of these organisms to zinc sulphate (ZnSO4·7H2O) was also determined. The following conditions were established for the protocol based on the best development of nauplii to copepodites: 72-h duration, the microalga Chaetocerus gracilis at 2.5×105cellsmL−1 as feed and incubation temperature of 28°C. In the zinc sulphate sensitivity tests, EC50−72h and LC50/72h were 3.25±0.59mgL−1 and 3.46±0.72mgL−1, respectively, as estimated by the final number of copepodites and total number of live animals in relation to the mean number of inoculated nauplii. The estimated NOEC was 2.0mgL−1. The test developed is fast and not labour intensive. T. biminiensis nauplii exhibit sensitivity to zinc sulphate similar to that of other species of copepods employed in water toxicity tests, demonstrating the usefulness of these organisms in ecotoxicological studies involving samples of environmental seawater.
•A practical toxicity test with Tisbe biminiensis nauplii to marine water was defined.•T. biminiensis nauplii sensitivity to zinc is similar to other copepod species.•The EC50−72h and LC50−72h of T. biminiensis nauplii to zinc were similar.
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