Environmental health reports

Water scarcity is an emerging issue in New Zealand and reducing water use is the first step in the “Reduce, Reuse and Recycle” hierarchy of water conservation. Wastewater can be treated and reused to reduce the use of potable water and freshwater resources, providing an alternative source of water for agriculture, urban activities and use by industry. However, while wastewater reuse provides benefits as an alternative source of water and nutrients, it also presents potential risks to human health and the environment.

The focus of this review is on the risk to human health from agricultural irrigation, urban and industry wastewater reuse. This review compares international guidelines on wastewater reuse, in particular how health risk is managed. The review can be a resource to support Public Health Officials making submissions on resource consent applications, plans and policies relating to wastewater reuse. It also provides a resource to support consistency in regulatory decision making on resource consents and in regional plans.

A review of international wastewater reuse standards and guidelines.pdf

This report is an air pollution health risk assessment for the Mount Maunganui area, prepared in response to a request by Toi Te Ora Public Health. The intent is to provide information to polluters, regulatory agencies, and the affected community on the potential scale of adverse health outcomes from existing air quality with the aim of working together to reduce discharges.

The approach taken has been to qualitatively and, where practicable, quantitatively describe and assess potential health risks of exposure to identified air pollutants in the Mount Maunganui area in accordance with good practice (WHO, 2014). The qualitative assessment reviews available data for the period ending 31 December 2021. The quantitative assessment uses a base year of 2019, which pre-dates potential impacts of the COVID-19 pandemic on ambient air quality.

Air Pollution: Health Risk Assessment Mount Maunganui

This report summarises and reviews Bay of Plenty Regional Council ambient air quality monitoring data from the Mount Maunganui Airshed for the years 2019 through 2022. The focus is on particulate matter (PM10 and PM2.5) and sulphur dioxide (SO2) which have previously exceeded national environmental standards for air quality. A brief review of Waka Kotahi NZ Transport Agency long-term monitoring data for nitrogen dioxide (NO2) in the Mount Maunganui Airshed for the period 2007 – 2021 is also provided.

Mount Maunganui Air Quality Monitoring Review 2022

Bacteria, viruses, parasites and fungi that can cause infection or illness in humans may be naturally found in beach sands or introduced with people or water entering the beach environment. In 2021, the World Health Organization (WHO) published updated guidelines for assessing and monitoring recreational coastal water quality, which recommended that risk factors for pathogens of concern in beach sand be incorporated into a recreational water safety plan. Coastal and marine water quality is monitored in Aotearoa New Zealand using faecal indicator bacteria (FIB) but it cannot be assumed that the presence of these FIB in water reflects the microbial risks from nearby beach sand. This report is a first step towards identifying which microbial hazards could pose a public health risk to New Zealand recreational beach use.

A review of the human health risks from microbial hazards in recreational beach sand

Although they are designed to treat illnesses and disease, exposure to pharmaceuticals present in the environment may be a hazard to human health and could enhance the evolution of antimicrobial resistance. This report is the result of a hazard assessment of pharmaceuticals in wastewater, focusing on one of the most hazardous groups of pharmaceuticals – cytotoxic drugs - which are mainly used to treat cancer.

More than 60 different cytotoxic drugs were dispensed annually in New Zealand during 2021 and 2022. Twenty-one of these drugs (the target drugs) had more than 5 kg dispensed annually (by mass not potency), and ten of these have been detected in municipal wastewater internationally. They may therefore be present in wastewater in New Zealand, although this would require further assessment. If detected in NZ wastewater, further studies assessing their presence in surface waters, groundwater and/or drinking water may be warranted.

Assessment of the potential health hazard posed by environmental exposure to cytotoxic pharmaceuticals in New Zealand

Transport activities have direct and indirect public health impacts, some of which are negative (e.g. air pollution) but others which are positive (e.g. increased physical activity). A well-designed transport system reduces reliance on non-renewable resources and fits into the natural and physical environment in ways which avoid, remedy or mitigate adverse effects. While New Zealand has guidance and tools to assess public health impacts associated with roading projects, impacts from land use are less well supported.

As part of the Health Risks from Transport Emissions in New Zealand research project, Emission Impossible Limited (EIL) were contracted to undertake this brief literature review on quantifying the health impacts of land use and transport emissions, including the ability to consider the benefits of alternatives.

Air quality-related public health impacts from land use and transport: Literature review

In 2020, the New Zealand Government introduced a four-tiered Alert Level system to help combat the spread of SARS-CoV-2, the virus that causes COVID-19. An unforeseen outcome of the extended restrictions in Auckland was that significant reductions in both daily and annual concentrations of two key pollutants, nitrogen dioxide (NO2) and particulate matter less than 2.5 micrometres in diameter (PM2.5), were observed. Research in this area has gone on to demonstrate the health benefits that may accrue from reductions in air pollution due to a reduction in vehicle movement, because of COVID-19 restrictions.

Air quality benefits of COVID-19 restrictions: Auckland case study 2020-2021

The transport sector – road, rail, maritime and aviation - emits a wide range of air pollutants which have associated adverse effects. In 2021, the Ministry of Health (MoH) funded a stocktake of the state of knowledge of the public health risks associated with transport emissions in New Zealand. That report (Part 1 of the Public Health Risks Associated with Transport Emissions in New Zealand) identified critical gaps, with the need to better understand the health impacts of exposure to nitrogen dioxide (NO₂) emissions from on-road motor vehicles at number one.

This report assesses the likely improvements in air pollution health impacts associated with meeting the targets for on-road vehicle greenhouse gas emissions in Te hau mārohi ki anamata | Aotearoa New Zealand’s First Emissions Reduction Plan. The key steps undertaken in the assessment were:

• Estimating the air pollution health impacts and social costs of motor vehicle emissions in 2019 to establish the baseline
• Assessing the change in motor vehicle emissions between 2019 and 2035 for business as usual (BAU) and scenarios representing the achievement of the various ERP targets (the scenarios)
• Calculating the associated air pollution health impacts and social costs of motor vehicle emissions in 2035 for BAU and the scenarios.

Public Health Risk associated with Transport Emissions in NZ: Part 2 Road Transport Emission Trends

Municipal wastewater and urban stormwater contain a wide variety of microbiological and chemical contaminants that may be of concern for human health. The presence and concentrations of specific contaminants can vary significantly depending on characteristics of the area, the nature and integrity of the network, and the climate. Based on a review of international iterature, this report identifies nine classes of contaminants present in wastewater and/or stormwater that are known to be, or highly likely to be, a human health hazard. Some of these contaminants and their associated health effects have long been recognised, but other 'emerging compounds' have not been well characterised and the potential health impacts are not well understood. To determine the potential risks to public health in Aotearoa New Zealand, further analysis is required to determine their presence in our wastewater and stormwater, understand their removal by locally-relevant treatment processes and consider the route and magnitude of exposure, in order to undertake specific risk characterisation and assessment.

Review of contaminants of potential human health concern in wastewater and stormwater

The ‘Interim New Zealand Guidelines for Cyanobacteria in Recreational Fresh Waters’ were released 2009. In 2018, the Recreational Cyanobacteria Guidelines were reviewed, with one of the recommendations being improvements to the alert-level framework (ALF) for planktonic cyanobacteria. The aim of the project was to revise the ALF for managing planktonic cyanobacteria in recreational waterbodies in-line with recommendations from the 2018 review. The majority of end-users who participated in the survey did not support the name change and it is recommended that it remains as is (a traffic light system).

2022 Revisions to the alert-level framework for planktonic cyanobacteria in the ‘New Zealand Guidelines for Cyanobacteria in Recreational Freshwaters'

Many New Zealand homes are known to suffer from mould and dampness. This may pose a health hazard due to the production of fungal infections, or mycoses, but also due to the production of toxic chemicals known as mycotoxins. Mycotoxin exposure in humans is usually associated with contaminated foods, but can also occur through inhalation and dermal contact in mould contaminated indoor environments. Traditional methods for assessing human exposure to mycotoxins primarily focus on dietary exposure. This report assesses the feasibility of specifically assessing exposure to mycotoxins present in the indoor environment using wastewater-based epidemiology (WBE).

Feasibility of assessing mycotoxin exposure in the indoor environment using wastewater-based epidemiology.

Harmful algae blooms (HABs) occur world-wide and Aotearoa New Zealand has experienced its share of significant bloom events. This report reviews how climate change will likely impact marine HABs in Aotearoa New Zealand and how these changes could affect public health. 

Climate change effects on marine harmful algal blooms in Aotearoa NZ

Climate change is already impacting freshwaters in Aotearoa New Zealand, and cyanobacteria, or blue-green algae, are expected to flourish with continued climate change. Many cyanobacteria species produce toxins that pose a health risk to animals and humans through physical contact, or by consuming them via contaminated water or aquatic foodstuffs. This review assesses the impact climate change will likely have on problematic cyanobacteria in Aotearoa New Zealand and how these changes could impact human health.

Climate change and toxic freshwater cyanobacteria in Aotearoa NZ

Agricultural activities discharge a range of contaminants into the air including greenhouse gases, ammonia, particulate matter, endotoxins, pathogens, volatile organic compounds, and odour as well as chemicals such as pesticides, herbicides, and fungicides. In New Zealand, livestock are known to be a significant source of greenhouse gases, however the potential public health risks associated with discharges to air from agriculture and agricultural practices in New Zealand have not been assessed. This review focusses on emerging issues related to agricultural activities that may be associated with risks for public health including particulate discharges to air from agriculture, and potential health risks associated with living near intensive livestock farms.

This is a preliminary scoping review to evaluate the relevance of these issues in New Zealand and identify data gaps.

Public Health Risks Associated with Discharges to Air from Agriculture in New Zealand: Scoping Review

• Health effects of air pollution
• Health effects of air pollutant factsheets: supporting information
• Health effects of long-term exposure to particulate matter (PM)
• Health effects of short-term exposure to particulate matter (PM), nitrogen dioxide (NO2) and ozone (O3)
• Health effects of long-term exposure to nitrogen dioxide (NO2) and ozone (O3)
• Effects of short-term exposure to nitrogen dioxide (NO2), ozone (O3) and sulphur dioxide (SO2) on asthma
• Health effects of short-term exposure to sulphur dioxide (SO2)
• Effects of carbon monoxide (CO) exposure on heart attacks

Untreated industrial effluents may contain a wide variety of contaminants of potential concern for human health. This report groups contaminants into seven broad classes: endocrine disrupting compounds, heavy metals and metalloids, per- and polyfluoroalkyl substances, pharmaceuticals, pesticides, microplastics, and contaminants of specific concern for tikanga Māori. To determine the potential health risks posed by these contaminants in the Aotearoa New Zealand context, further analysis is required.

Review of potential health hazards associated with industrial effluents

Transportation in New Zealand – which encompasses road, rail, maritime transport and aviation – emits a wide range of air pollutants, many of which present a public health risk. The adverse effects of transport emissions are significant in New Zealand. The social costs of transport-related harmful air pollution are currently estimated at $1.21 billion per annum (in $2019) as a result of New Zealanders dying prematurely, being admitted to hospital or suffering days lost due to illness or poor health. Transport sources also emit direct or indirect climate pollutants. Transport-related greenhouse gas emissions add an additional $1.68 billion in social costs per annum (in $2019).

This report is the first step in addressing the research question: “What are the risks to public health associated with road, sea, rail and air travel including vessel emissions, dusty roads and vehicle emissions in New Zealand?” It draws on a stocktake and gap analysis of the current state of knowledge across various transportation sectors as at 30 June 2021.

Public Health Risks associated with Transport Emissions in NZ report: Part 1 Stocktake and Gap Analysis

When building materials become damp, fungal spores and bacteria present in indoor air and dust can colonise the building materials and grow, producing visible contamination (mould). Inhalation of mould has been associated with allergic reactions, toxic and irritant effects and infections.

Indoor mould growth can be prevented or minimised by actively maintaining, inspecting, and correcting buildings for moisture problems and immediately drying and managing water-damaged materials. However, necessary steps are not always taken and given the potential for adverse human health effects, it is important that mould occurring in the indoor environment be removed and that the cause of the high moisture contents also be addressed.

This report considers two bodies of information:

• Advice, provided by various organisations, on approaches for the removal of mould
• Evidence for the efficacy of approaches for the removal of mould

Decontamination of mould-affect environments report

Of the 1.47 billion tonnes of solid waste that is produced each year globally, 5.9 million tonnes (approx. 16,164 tonnes per day) are estimated to be a result of health care waste. This figure has increased year on year, and the COVID-19 pandemic has served as an extreme example of the challenges for sustainable health care waste. Aotearoa New Zealand's health care sector is estimated to contribute between 3% and 8% of national carbon dioxide equivalent (CO₂e) emissions. For comparison, the UK and the USA emit 4% and 10%, respectively, of their national CO₂e from health care. Efforts are required to reduce waste production, landfill use and unnecessary procurement costs that arise from district health board activities, thus realising financial, environmental, cultural, health, wellbeing and social benefits.

From Health Sector Waste Minimisation Towards a Circular Economy