The transfer of plastic waste from developed to developing countries poses a significant environmental problem due to the difficulty in handling the waste, which often contains hazardous chemical additives. Plastics from used electronics and consumer products, especially those containing flame retardants, are of particular concern, as they release toxic substances like polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), and brominated dioxins (PBDD/Fs) into the environment. Numerous studies have identified thousands of chemicals in plastics, many of which are not adequately regulated globally. Developing countries, lacking appropriate disposal technologies, often resort to open burning to extract metals from plastic waste, causing the release of even more toxic chemicals, including dioxins. Global flows of pollutants like PBDEs have been observed, showing a transfer of emissions from developed to developing regions. These chemicals contaminate food chains and pose health risks to local communities. One concerning practice is the use of plastic waste as fuel in local industries, releasing toxic pollutants like dioxins and furans. Free-range chicken eggs, sensitive indicators of contamination, have revealed significant levels of persistent organic pollutants (POPs) at various sites impacted by plastic waste disposal. E-waste, a major source of plastic waste treated with brominated flame retardants (BFRs), is also improperly recycled in low-income countries, resulting in further pollution. To combat this issue, better waste management practices, including improved regulation and disposal methods, are crucial. Developing countries must address the hazardous implications of plastic waste importation and find sustainable solutions to prevent environmental and health hazards caused by improper waste disposal. Increasing volumes of plastic waste and toxic chemical releases globally led to the conclusion that humanity is currently operating outside the planetary boundary.

BACKGROUND:Children and consumers are exposed to increasingly complex mixtures of known and as-yet-unknown toxic chemicals from toys and products. However traditional chemical analysis methods only evaluate a small number of chemicals at a time thereby restricting consumer awareness of the full range of potentially harmful chemicals in products. METHODS:We used high-throughput effect-based non-animal methods to investigate exposures to complex chemical mixtures of several kinds of brominated flame retardants (BFRs) for their dioxin- and thyroid hormone-like activities in various kinds of consumer products and toys from 26 different countries, on four continents (Africa, America, Asia and Europe) in combination with chemical analysis of various polybrominated flame retardants (BFRs) and their impurities (such as polyhalogenated PCDD/Fs and PBDD/Fs). RESULTS:We found high levels of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in toys and now, for the first time, also in consumer products that are manufactured from black plastics containing certain brominated flame retardants (BFRs). The presence of PBDD/PBDFs as well as other BFRs in various black plastic materials from additional countries as well as additional kinds of consumer products as confirmed by effect-based in vitro reporter gene DR CALUX and TTR-TRβ CALUX assays as well as congener-specific chemical analysis. We compared total Toxicity Equivalent (TEQ) levels of PBDD/F-TEQs analysed by chemical analysis to by CALUX bioassay measured Biological equivalence (BEQ) concentrations (for further info see at ISO 23196, ISO, 2022). In the case of TBBPA, both chemical and TTR-TRβ CALUX analysis measure direct the amount of TBBPA. Finally, the daily ingestion of 2,3,7,8-TCDD equivalents from PBDD/Fs-contaminated plastic toys by child mouthing habits have been related to our earlier study (Budin et al., 2020). CONCLUSIONS:Interaction of children with such contaminated plastics may significantly contribute to the daily uptake of dioxin- and thyroid hormone transport disrupting-like compounds. Effect-based bioassays for dioxin- and thyroid hormone-like activities are relevant to pick-out such complex mixtures of known and yet unknown (and therefore not regulated) substances for safer and more sustainable plastics. Low POPs Content Levels and other mechanisms set under the Basel and Stockholm Conventions are set far too high to prevent a significant flow of BFRs and PBDD/Fs into consumer products.

This review compiles information on PCDD/F- and PCB-contaminated eggs from 20 years of global egg monitoring around emission sources in four continents conducted by the International Pollutants Elimination Network (IPEN) and Arnika as well as a compilation of data from scientific literature. IPEN monitored 127 pooled egg samples including samples from 113 chicken flocks at potential PCDD/F- and PCB-contaminated sites around priority sources listed in the Stockholm Convention (e.g. waste incinerators, metal industries, cement plants, and open burning). 99 (88%) of pooled egg samples were above the EU maximum limits for PCDD/Fs (2.5 pg PCDD/F-TEQ/g fat) or the sum of PCDD/Fs and dioxin-like PCBs (5 pg PCDD/F-PCB-TEQ/g fat). Children consuming such eggs exceed the tolerable weekly intake (TWI). This demonstrates that close to 90% of these areas were not safe for the production of free-range eggs. Sixteen out of the 113 egg samples (14%) were contaminated above 50 pg TEQ/g fat and exceeded the EU maximum limit more than 10 times. From the 26 pooled egg samples around incinerators 24 (92%) exceeded the limit with a mean of 43.1 pg TEQ/g fat (2.6–234 pg TEQ/g). All 21 egg samples around metal industries (4.4–112.6 pg TEQ/g fat) were above limits with mean concentration of 26.0 pg TEQ/g fat. Also all 7 egg samples measured at e-waste recycling sites were above limits (mean 308 pg TEQ/g fat). In 58 (51%) pooled egg samples the PCB-TEQ was above 5 pg TEQ/g fat exceeding the EU maximum limit with dioxin-like PCBs alone. This highlights the role of commercial PCBs for global contamination with dioxin-like compounds. It was discovered that around metal industries, shredder plants, open burning sites of e-waste and dump sites, a high share of contamination was caused by dl-PCBs. This clearly shows severe PCB release from the end-of-life management of PCB-containing equipment in developing countries. Also highly contaminated eggs were found at many sites where plastic was incinerated. The highest contaminated egg sample ever measured came from an e-waste site in Ghana and had 856 pg TEQ/g fat plus 300 pg TEQ from brominated dioxins (PBDD/Fs). Other extreme PCDD/F contaminations of eggs were found at a chlor-alkali site (514 pg TEQ/g fat), Agent Orange contaminated areas in Vietnam (490, 249 and 246 pg TEQ/g fat) and e-waste sites (568 and 520 pg TEQ/g fat). Where DR CALUX® bioassay revealed higher TEQ compared to measured PCDD/F-PCB-TEQ in IPEN studies, polybrominated PBDD/F were also measured and detected up to 300 pg TEQ/g fat at e-waste sites. One positive outcome from the IPEN studies is that all 10 pooled supermarket eggs in developing countries were below regulatory limit. Policy recommendations are made including: a systematic assessment of areas around PCDD/Fs and PCBs sources; measures for reduction of exposures of populations; urgent control of emission sources including PCB equipment, the open burning of plastic, and the use of plastic as fuel in boilers/incinerators in developing countries without air pollution control. Furthermore, soil limits need to be re-assessed and lowered for free-range poultry.