Filling the Knowledge Gap: Federal Government Releases Draft Science Assessment of Plastic Pollution
In recent years, the issue of plastic pollution and its impacts on human health and the environment has emerged as a global concern. As part of efforts to understand the current state of science in Canada regarding the potential impacts of plastic pollution on the environment and human health, Environment and Climate Change Canada (ECCC) has released a Draft Science Assessment of Plastic Pollution (the Draft Assessment). The Draft Assessment, which sheds light on the extent of the plastic pollution issue in Canada, was published on January 30, 2020 in Part I of the Canada Gazette for a 60-day public comment period (ending April 1, 2020).
To reduce plastic waste in Canada, the federal government announced in June 2019 that it will ban single-use plastics as early as 2021. The ban is expected to include items such as plastic bags, straws, cutlery, plates and stir sticks. The federal government will also work together with the provinces and territories to introduce Extended Producer Responsibility (EPR) programs, which will help to establish standards and targets for companies that manufacture plastic products or sell items with plastic packaging. A more detailed overview of the federal government’s proposed plastic reduction measures is set out in our earlier blog. These measures align with similar actions being taken in the European Union and other countries. In addition, these initiatives complement Canada’s adoption of the Ocean Plastics Charter in June 2018, which lays the groundwork for ensuring that plastics are designed for reuse and recycling. In addition, the federal government’s efforts to reduce plastic pollution includes ongoing work through the CCME to develop an action plan to implement the Canada-wide 2018 Strategy on Zero Plastic Waste.
Summary of the Draft Assessment
The purpose of the Draft Assessment is to survey the existing state of science on plastic pollution (including its sources, occurrence, and fate, as well as on the potential effects of plastics on the environment and human health) in order to guide future research and inform regulatory activities within the context of managing plastic pollution in Canada. A summary of the key findings of the Draft Assessment is set out below:
- Plastic pollution, in the form of macroplastics (plastics larger than 5 mm) and microplastics (plastics equal to or less than 5 mm), is ubiquitous in the environment. It is estimated that in 2016, 1% of all plastic waste in Canada (or 29 kt), was discharged to the environment as litter.
- The rate at which plastics break down is very slow and can be affected by multiple factors, such as temperature and light. In water, the rate of degradation is temperature dependent, being slower in cold water. The lack of exposure to sunlight also slows down the degradation of plastics. While oxidation can promote the degradation of plastics in soil, the rate of degradation is still slow. Although biodegradable plastics and bioplastics are increasingly being used as alternatives to conventional plastics, they may not degrade more readily than conventional plastics once in the environment. Since plastics degrade very slowly and are persistent in the environment, the frequency of occurrence of plastic pollution in the environment is expected to increase.
- Plastic packaging is the biggest contributor of plastic waste in Canada, followed by the automotive, textile, and electrical and electronic equipment sectors. The release of synthetic microfibres from wastewater treatment systems (WWTS) is also anticipated to represent a significant source of microplastic pollution. In WWTS, microplastics removed from wastewater settle in sewage sludge and are then released to land through the application of biosolids. The presence of microplastics in outdoor air is largely thought to be attributable to tire wear and tear, while microplastics in indoor air result from the shedding of fibres from clothing, furniture, carpeting and household goods.
- Plastic pollution is found everywhere in the environment. In Canada, single-use plastics make up the bulk of plastic litter that is found in freshwater environments. The most common litter items collected on Canadian shorelines include bottle caps, plastic bags, plastic bottles, straws, and cigarette butts. Large numbers of microplastic particles are also found in fresh and marine surface waters. Globally, microfibres are the most abundant type of microplastics found in water. Microplastics are also found in sediment and soil. ECCC recognizes that there is a lack of standardized, high-quality methods for sampling plastics, particularly for measuring and characterizing microplastics.
- Air is also anticipated to be an important pathway for microplastic transport, and microplastics have been detected in both indoor and outdoor air. While there are no Canadian data available on the occurrence of microplastics in air, data from other parts of the world show that concentrations are higher in indoor air than in outdoor air. Indoors, microplastics are also found in settled house dust.
- Current data on the occurrence of microplastics in food are limited, and most available information concerns microplastics found in seafood, specifically fish and shellfish from marine environments. In fish, microplastics have been found in both muscle tissue and the gastrointestinal tract, mostly as fragments and fibres. Microplastics have also been detected in mussels, clams, oysters, scallops and snails, and in a very small number of other foods, such as salt.
- Internationally, a limited number of studies have investigated the presence of microplastics in tap and bottled water. Microplastics have been detected in up to 93% of bottled water samples from outside of Canada, with concentrations varying across bottle type (i.e. plastic, glass or cardboard) and intended use conditions (i.e. single-use versus multi-use bottles). In the case of tap water, some studies have detected microplastics while others have not. Drinking water treatment is anticipated to remove a large proportion of microplastic particles.
- Plastic pollution has been shown to impact organisms and their habitats. Macroplastic pollution can cause physical harm to biota, often as a result of entanglement or ingestion. Entanglement can lead to suffocation, strangulation, or smothering, and a high frequency of reported entanglement occurrences has led to the direct harm or mortality of biota. Ingestion can lead to direct harm through physical damage; it can block airways or intestinal systems leading to suffocation or starvation.
- Humans may be exposed to microplastics via the ingestion of food, bottled water, and tap water, as well as through the inhalation of indoor and outdoor air. However, information on the human health effects of microplastics is limited. Some associations between exposures to high levels of microplastics and adverse health effects in laboratory animals and in humans have been reported, but the health effects cannot be linked to exposure in the general population. Occupational inhalation exposure studies show associations between work in microplastic-related industries and increased incidence of various respiratory symptoms and diseases. Conflicting observations have been made for cancers of the respiratory tract and digestive system.
- In addition to physical impacts, there are concerns that plastics may serve as a means of transport for other chemicals. Since plastics can contain unbound monomers and chemical additives and can sorb persistent organic pollutants from the environment, it is possible that these substances may be transported to organisms or humans, where they may then be released. The extent of release is expected to depend on a variety of factors, such as the properties of the receiving environment, the plastic particle, and the bound chemical.
The Draft Assessment notes that under the precautionary principle, action is needed to reduce macroplastics and microplastics that end up in the environment. In addition, the Draft Assessment recommends further research in order to advance the understanding of the impacts of plastic pollution on the environment and human health. In particular, the Draft Assessment identifies the following knowledge gaps:
- the need to develop standardized methods for sampling, quantifying, characterizing, and evaluating the effects of macroplastics and microplastics;
- the need to further the understanding of human exposure to microplastics;
- the need to further the understanding of the eco-toxicological effects of microplastics;
- the need to further the understanding of the effects of microplastics on human health; and
- the need to expand and develop consistent monitoring efforts to include poorly characterized environmental compartments such as soil.
Increasing Knowledge on Plastic Pollution Initiative
In order to address the knowledge gaps identified above, ECCC and Health Canada have launched the Increasing Knowledge on Plastic Pollution (IKPP) Initiative. The IKPP program aims to increase capacity, leverage collaborative partnerships and generate knowledge in support of Canada’s Plastics Science Agenda, with a particular focus on research gaps identified in the Draft Assessment. Projects that look at the potential human health effects and ecotoxicology of plastics in Canada may be eligible for funding. Applications for funding can be submitted through the Grants and Contributions Enterprise Management System until March 20, 2020.
Public Comment Period
As noted above, the Draft Assessment is open for a 60-day public comment period, which will end on April 1, 2020. Public comments will inform the final science assessment. All comments must cite the Canada Gazette, Part I, the date of publication of the notice (February 1, 2020) and be addressed to the Executive Director, Program Development and Engagement Division, Department of the Environment, Gatineau, Québec, K1A 0H3. Comments may also be submitted by fax to 819‑938‑5212, by email to [email protected], or by using the online reporting system available through Environment and Climate Change Canada’s Single Window.
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