The environmental fate of chemicals – a context for learning
There are over 150,000 substances approved for use in Aotearoa New Zealand that contain an estimated 30,000 chemicals.
We use chemicals on a daily basis – they’re all around us. Chemicals are not inherently bad. Many – like medicines or fertilisers – provide some benefit to society. When chemicals are used in the way that they are approved for and the approval process has taken into account their likely environmental fate, the chemicals we find in the environment should be at acceptable levels. Questions arise when chemicals migrate from the intended application to the environment.
Knowing what’s out there report cover
Details from the cover of the Parliamentary Commissioner for the Environment report Knowing what’s out there: Regulating the environmental fate of chemicals .
A PDF of the report can be downloaded here .
Photos on cover: Autosampler vials, Matthew Bates, Flickr; culvert drain, Megan Martin; maize field, pxhere.com.
When chemicals enter environments where they are not usually present or in quantities above naturally occurring levels, they can cause problems for living things. The article Chemical contamination in the environment summarises the Parliamentary Commissioner for the Environment report, which questions the adequacy of the information on which we base important environmental decisions.
Many natural systems and problems are complex. Complexity concepts and dynamics have not been part of a traditional science curriculum but should be considered as an important new element , given the complex nature of many urgent issues that face us.
Enduring competencies for designing science learning pathways, NZCER 2022
Exploring socio-scientific issues and the nature of science
The use, impacts and fate (end point) of chemicals in the environment is a socio-scientific issue. Addressing socio-scientific issues in the classroom can provide a context for developing understanding of science knowledge, scientific processes and the nature of science. It also shows how science is socially and culturally embedded as it highlights the intricate relations between science, technology and society – including the cultural, social, economic, political, ethical and environmental implications.
Socio-scientific issues are complex and require scaffolding to be an effective learning tool in the classroom. Often an inquiry-based approach is utilised when exploring socio-scientific issues. For complex issues such as the environmental fate of chemicals, the teacher may not necessarily be an expert but will be a facilitator of the process of inquiry. Providing the opportunities to elicit students’ prior knowledge about the issue will often uncover misconceptions as well as different levels of knowledge and students’ beliefs and values in relation to the issue. By engaging in an inquiry process, the students can develop new understandings, often raising further questions driven by their own learning journeys and curiosity – much like practising scientists. Inquiries can also be scaffolded to support ākonga to identify, articulate and justify their own views about complex issues.
In any issue, ākonga need to sort out what parts of the issue require a scientific lens and what parts require other lenses.
For example, when exploring an issue, ākonga need to identify and understand:
what scientific knowledge is relevant
how reliable the knowledge is
how the knowledge was gathered
the limits of the knowledge
how much confidence we can have in that knowledge
te ao Māori perspectives, including relevant local mātauranga Māori
additional cultural, social and ethical considerations – local, national and/or global.
The Hub has articles on three case studies featured in the report Knowing what’s out there: Regulating the environmental fate of chemicals:
Zinc – used in industrial, household, human and animal health products.
Tetracycline antibiotics – in New Zealand they are mainly used to treat farm and companion animals.
Neonicotinoid insecticides – used on food crops and for household uses.
These articles provide information on why and how we use the various products in Aotearoa, their chemical structures, pathways into the environment and key concerns and impacts.
Properties and processes that influence if and how chemicals reach the environment
This figure illustrates the physical and chemical properties that influence what happens to chemicals in the environment and the biological and ecological processes that can result in toxicity to living things.
Diagram adapted from the National Research Council, 2014.
Science concepts, mātauranga Māori and curriculum links
Science and mātauranga Māori concepts that underpin each of the case studies include:
ecosystem interactions and potential impacts on non-target organisms
properties and processes that affect chemical transport, including solubility and adsorption
persistence, degradation or transformatio n of chemicals released in the environment
cellular resistance mechanisms
what constitutes a toxin and a toxic dose
people are an interconnected part of an ecosystem
acknowledging relationships between all living organisms impacts the practices of being ethical and responsible.
The case studies support science learning primarily in the Material World strand:
Structure of matter: chemical processes; structure and bonding.
Chemistry and society: groups of substances and how they are used; meeting needs, resolving (or creating) issues and development of new technologies.
They also support learning about Earth systems and interacting systems in the Plane t Earth and Beyond strand and learning about human actions on ecosystems in the Living World strand.
When young people are confronted with real-life events, opportunities, and challenges, or issues of concern and interest to them, they know how and when to draw on their science knowledge and skills, or their mātauranga Māori knowledge and skills, to act in the world. They are prepared to act responsibly and ethically on these issues with an awareness of the interconnectedness of things and events in both the natural and social world.
Enduring competencies for designing science learning pathways, NZCER 2022
Neonicotinoids in the environment
Environmental fate and exposure of neonicotinoids to target and non-target organisms when applied as a seed coating.
Source: Sánchez-Bayo, Francisco. (2014). The trouble with neonicotinoids. Science . 346. 806-807. 10.1126/science.1259159.
The environmental fate of chemicals – questions to consider
Simon Upton, Parliamentary Commissioner for the Environment, writes, “We need to ask the right questions about the things that matter.” Questions can help guide an inquiry approach to learning about chemicals we use, their fate, regulations about their use and why this matters.
Zinc is a naturally occurring chemical – how does it become an environmental issue?
Neonicotinoids were developed to reduce harm to non-target vertebrates – why is there growing concern about their use?
Do the advantages of antibiotics outweigh what appear to be low to medium environmental risks?
What are some physicochemical properties that influence what happens to chemicals in the environment?
What are some soil/water processes that influence what happens to chemicals in the environment?
What causes a substance that is beneficial in one setting to become a toxin in another setting?
What are the unintended consequences of useing substances such as insecticides or antibiotics?
Should we have national guidelines or guidelines for smaller, more localised areas?
Are there ethical considerations to examine?
What are the rights and responsibilities of those who use and/or regulate the use of a particular chemical substance? Who decides on these rights?
Do the benefits of using a chemical product outweigh the potential harm? What are the alternatives?
Are international guidelines adequate for protecting endemic taonga species?
Related content
Investigating toxins – key terms includes a number or terms used when looking at the environmental fate of chemicals.
The Ethics thinking toolkit provides a structured framework for scaffolding student thinking about an ethical issue.
To build knowledge about contamination and toxicity, take a look at Soil contamination, Keeping it clean, Estuaries and farmland run-off, How harmful are microplastics? and Environmental toxicity after Rena .
Learn about Disinfecting wastewater and understand how scientists research adverse impacts on the quality of drinking water, recreational water and wastewater and the measures taken to manage them in the article ESR Water Management Group.
Read about how contaminated sites are cleaned up in Treatments for acid mine drainage, Cleaning up the oil spill and Restoring mauri after the Rena disaster.
For solutions and actions to better protect the environment from contamination, go to Waitī – freshwater environments, Urban solutions for water quality or Managing nutrients.
Environmental issues are suited to inquiry investigations. This PLD interactive guides you through the process.
See how different schools have used action to support learning in Students help restore mauri to the Oruarangi Stream and Down the drain.
Useful link
Access the PCE report Knowing what’s out there: Regulating the environmental fate of chemicals.
For further data and details on the neonicotinoids case study, refer to pages 91–99 and 147–153.
For further data and details on the tetracyclines case study, refer to pages 99–106.
For further data and details on the zinc case study, refer to pages 115–124.
Acknowledgement
This resource has been created from Knowing what’s out there: Regulating the environmental fate of chemicals and associated resources with support from the office of the Parliamentary Commissioner for the Environment.
Parliamentary Commissioner for the Environment logo
The Parliamentary Commissioner for the Environment is one of three Officers of Parliament that work in an independent watchdog capacity, helping Parliament hold to account the government of the day.
