Toxicity of Electronic Waste Leachates to Daphnia magna: Screening and Toxicity Identification Evaluation of Different Products, Components, and Materials

Abstract

Electronic waste has become one of the fastest growing waste problems in the world. It contains both toxic metals and toxic organics. The aim of this study was to (1) investigate to what extent toxicants can leach from different electronic products, components, and materials into water and (2) identify which group of toxicants (metals or hydrophobic organics) that is causing toxicity. Components from five discarded electronic products (cell phone, computer, phone modem, keyboard, and computer mouse) were leached in deionised water for 3 days at 23°C in concentrations of 25 g/l for metal components, 50 g/l for mixed-material components, and 100 g/l for plastic components. The water phase was tested for acute toxicity to Daphnia magna. Eighteen of 68 leachates showed toxicity (with immobility of D. magna ≥ 50% after 48 h) and came from metal or mixed-material components. The 8 most toxic leachates, with 48 h EC(50)s ranging from 0.4 to 20 g/l, came from 2 circuit sheets (key board), integrated drive electronics (IDE) cable clips (computer), metal studs (computer), a circuit board (computer mouse), a cord (phone modem), mixed parts (cell phone), and a circuit board (key board). All 5 electronic products were represented among them. Toxicity identification evaluations (with C18 and CM resins filtrations and ethylenediaminetetraacetic acid addition) indicated that metals caused the toxicity in the majority of the most toxic leachates. Overall, this study has shown that electronic waste can leach toxic compounds also during short-term leaching with pure water.

Variability in Toxicity of Plastic Leachates as a Function of Weathering and Polymer Type: A Screening Study with the Copepod Nitocra spinipes

“…The keyboard was selected as a positive control because of the potentially high levels and numbers of additives. However, in the study by Lithner et al (2012), no toxicity to Daphnia magna was observed after being exposed to leachates from a keyboard (Lithner et al, 2012). These differences might be because Lithner et al used an old keyboard, exposed it only for three days in water, and used a different test organism than was used in the present study.…”

Assessing the Toxicity of Leachates From Weathered Plastics on Photosynthetic Marine Bacteria Prochlorococcus

“…While this work sheds light on the potential for environmental weathering to affect the composition and toxicity of plastic leachates, it is important to point out that these experiments were conducted using methodology based on previous leachate ecotoxicology testing (Lithner et al, 2012a) rather than seeking to mimic environmental exposure scenarios. Indeed, it is difficult to determine what marine bacteria in the oceans may currently experience in terms of leachate exposure, as there are very few measurements of the substances that leach from plastic debris, or their concentrations, in the marine environment.…”

The Potential Risk of Electronic Waste Disposal into Aquatic Media: The Case of Personal Computer Motherboards

“…Based on a real-life scenario, the present study revealed that the direct disposal of PCBMs into fresh- and saltwater bodies could lead to the release of different types of chemical substances, even after a leaching period of 30 days. Similarly, Lithner et al [ 31 ] reported that different discarded electronic products can leach toxic compounds during a short-term (3 days) period of leaching into pure water (pH 7, 23 °C), while Almeida et al [ 21 ] reported that PCMBs trace elements could be leached into DW (pH 4.8) even after the first days of a prolonged leaching period (120 days). According to the latter, it seems reasonable to suggest that even under mild leaching conditions, in terms of constant temperature and natural to alkaline pH values ((pH 7–8, 17 °C), inorganic anions, trace elements, and organic toxicants can be leached by PCMBs into both media tested.…”

“…No size reduction or dismantling of the PCMBs components was conducted before and during the test. DW selection as leaching medium was based on its further usage for preparing algal culture medium and conducting CBMN assay, thus avoiding interferences and equivocal results, while the CPBM leaching period was 30 days, according to previous studies that showed the presence of PCMBs leaching chemicals into the aquatic media [ 21 , 31 ]. In parallel, tanks containing PCMB-free DW and/or ASW were used as reference ones.…”