(September 28, 2019) Currently, plastic is at the top of the international agenda for waste management. Recent meetings of the Conferences of the Parties to the Basel and the Stockholm Conventions have expressed concerns over the impact of plastic waste, marine plastic litter, and microplastics, and emphasised the importance of reducing consumption and ensuring the environmentally sound management of waste plastics. This study presents the first continental historical analysis of mass importation and consumption of different polymers and plastics (primary and secondary forms, respectively) in Africa and the associated pollution potential. We identified, collated and synthesised dispersed international trade data on the importation of polymers and plastics into several African countries.
Results
The 33 African countries (total population of 856,671,366) with available data for more than 10 years imported approximately 86.14 Mt of polymers in primary form and 31.5 Mt of plastic products between 1990 and 2017. Extrapolating to the continental level (African population of 1.216 billion in 54 countries), about 172 Mt of polymers and plastics valued at $285 billion were imported between 1990 and 2017. Considering also the components of products, an estimated 230 Mt of plastics entered Africa during that time period, with the largest share going to Egypt (43 Mt, 18.7%), Nigeria (39 Mt, 17.0%), South Africa (27 Mt, 11.7%), Algeria (26 Mt, 11.3%), Morocco (22 Mt, 9.6%), and Tunisia (16 Mt, 7.0%). Additionally, primary plastic production in 8 African countries contributed 15 Mt during 2009–2015. The assessment showed that environmentally sound end-of-life management of waste plastics by recycling and energy recovery is in its infancy in Africa, but recycling activities and thermal recovery have started in a few countries.
Conclusions
Globally, the perception is that production and consumption of plastics can only increase in the future. Solutions are needed to tackle this global challenge. Certain policies and plastic bag bans could help reduce plastic consumption in the near future, as demonstrated by Rwanda. Furthermore, there is a need for innovative solutions such as the introduction of biodegradable polymers and other alternatives, especially for packaging.
Background
In recent decades, the production and consumption of plastics have increased owing to increasing applications that rely on the good characteristics of plastics such as light weight, strength, durability, affordability, corrosion resistance and low production costs [1]. Between 1950 and 2015, about 8300 million tonnes (Mt) of virgin plastics were produced across the globe, generating approximately 6300 Mt of plastic wastes, of which around 9% have been recycled, 12% incinerated, and 79% accumulated in landfills [2]. Current worldwide production of plastics is around 300 Mt/year, with 57 Mt/year produced in the European Union [3]. Globally, the yearly average per capita plastic consumption is 43 kg [4]. In India, the consumption of plastics increased from 0.4 Mt/year in 1990 to 4 Mt/year in 2001, and it was expected to rise to 8 Mt/year in 2009 [5] and 16.5 Mt/year in 2017/18 [6]. In Asia, plastic use is 20 kg/capita/year, while in Western Europe and North America the average is 100 kg/capita/year [7]. Plastic consumption increases with GDP [8].Footnote 1 Waste plastic represents a considerable proportion of the total waste stream in many countries. The total mismanaged plastic waste globally in 2010 was estimated at 32 Mt [9]. Currently, plastic waste poses human and environmental issues globally and especially for African countries, which have a high proportion of mismanaged waste plastics and lack state-of-the-art recycling facilities [10].
Depending on type and use, plastic contains a wide range of additives such as plasticizers, flame retardants, antioxidants, acid scavengers, light and heat stabilisers, lubricants, pigments, antistatic agents, slip compounds, and thermal stabilizers. These additives are used in plastics for various purposes [2, 11,12,13,14]. Many of these additives have toxic effects and some are classified as endocrine disrupting chemicals [EDCs; e.g. bisphenol A or diethylhexylphthalate (DEHP)]. Several others have been listed as persistent organic pollutants (POPs), including the flame retardants polybrominated diphenyl ethers (PBDEs), hexabromobiphenyls (HBB), hexabromocyclododecane (HBCD), short-chain chlorinated paraffins (SCCPs) and the fluorinated tensides like perfluorooctanoic acid (PFOA). The largest share of plastics however is not flame retarded and does not contain POPs as additives.
Inappropriate use and disposal of waste plastics may result in the release of toxic substances, which is facilitated by open burning of e-waste plastics from vehicles and cables [15,16,17,18]. Hazardous chemicals can also migrate from the plastic matrix leading to exposure via direct contact, for example from toys or kitchen tools that are partly produced from recycled plastic [15] or soft PVC used in toys or medical devices [19, 20]. On the other hand, additives in food packaging plastics or water bottles are controlled and regulated in industrialised countries. In Africa, the regulations on plastic additives and other chemicals in products are weak [21, 22].
Furthermore, most polymers are resistant to degradation, thus most plastic debris may persist in the environment for decades or centuries [22, 23] and may be transported far from the source [1]. An estimated over 4 Mt of plastic waste generated on land entered the marine environment in 2010 alone [9]. Currently this is estimated at 8 Mt/year [4]. The most common monomers used to make plastics are derived from fossil hydrocarbons and the resulting products are not biodegradable [2], hence the high persistence in the environment.
Currently, plastic is at the top of the international agenda for waste management. Recent meetings of the Conferences of the Parties to the Basel and the Stockholm Conventions “encouraged regional and coordinating centres to work, under the Convention, on the impact of plastic waste, marine plastic litter, microplastics and measures for prevention and environmentally sound management” [14]. Mixed plastic waste was listed in the Basel Convention Annexes as hazardous waste to control during international trade [24]. The global problem of increasing plastic waste and the associated pollution, marine litter, biodiversity and human health effects were recognised at each of the first four meetings of the United Nations Environment Assembly (UNEA 4). UNEA 4 addresses the analysis of voluntary commitments targeting marine litter and microplastics pursuant to Resolution 3/7 (UNEP/EA.3/Res.7.).
In a previous study, we compiled primary data on plastic imports into Nigeria [25]. Our study revealed that large amounts of plastics have entered Nigeria over the years, but robust continental-scale information is still lacking in Africa. Many data gaps have been identified in Africa concerning plastics and the associated wastes [10]. We present the first historical analysis of mass importation of polymers and plastics in primary and secondary forms and the associated pollution potential in Africa by identifying and synthesising dispersed international trade data on plastic importation and local production. The connection between trade and inventory data and the waste and pollution potential can eventually be used as a tool to develop counter-measures, improve prevention and management programmes, and calculate recycling quotas [25]. We also assessed the volume of wastes arising from plastic products and the recycling status in African countries.