Clean Air Blog

Smoke can affect air quality in New Zealand at any time of year, not just during summer wildfires. Winter woodburners, controlled burns, industrial or vehicle fires, building fires, and even smoke drifting over from Australia can all push PM2.5 levels up. Events like the Port Hills Fire in Christchurch (Feb 2024) show how quickly air quality can change and how important it is to know what to do. Whether smoke is coming from your neighbour’s chimney, a nearby scrub fire, or a major incident, the aim is the same: keep PM2.5 out of your lungs and out of your home as much as possible. 1. Why Smoke Is Harmful, Understanding PM2.5 Smoke contains a mix of gases and particles, but the main concern is PM2.5: particles small enough to enter deep into the lungs and even the bloodstream. PM2.5 can: Irritate the throat, nose and eyes Worsen asthma and allergies Aggravate heart and lung conditions Cause headaches and poor sleep Build up indoors unless removed In NZ, winter woodburners regularly cause PM2.5 spikes — especially on still nights that trap smoke near the ground. Large events like the Port Hills Fire or Australian bushfire drift can cause very high short-term levels as well. If you can see or smell smoke, assume PM2.5 is elevated. 2. Keeping Smoke Out of Your Home Health NZ’s general advice during smoke events is simple: Stay indoors if possible Close all windows and doors Reduce outdoor air getting inside You can see their full guidance here → Here’s how to put that into practice at home: Close and seal your home Shut windows and doors Use curtains, door snakes, or towels to block gaps Avoid creating drafts Turn off ventilation systems that pull in outdoor air Systems such as HRV or positive-pressure ventilation often draw outside air in, and most cannot effectively filter out PM2.5. Turn these off during smoke events unless your system has a HEPA intake filter. Heat pumps are fine, they recirculate indoor air and don't draw in smoke. Reduce indoor PM2.5 contributors These activities make indoor smoke levels worse: Frying or grilling Burning candles or incense Vacuuming (which stirs up dust) Smoking indoors Keep indoor air as stable as possible. Create a Cleaner Air Space Indoors Pick a room (often a bedroom or living area) and keep the air in there as clean as possible by: Keeping windows and doors shut Reducing drafts Avoiding dust-creating activities Running a HEPA purifier This room becomes your safest indoor space during heavy smoke. 3. Checking Air Quality in NZ Smoke levels can shift quickly, whether from woodburners, fires, or drifting smoke. Checking air quality helps you know when to seal the home and when to ventilate. One challenge is that air-quality monitoring in NZ is limited.Even with community networks like PurpleAir and AirGradient, many towns and rural areas have no sensors at all. Official monitoring is even more restricted. These are the most useful tools: IQAir (best real-time map — aggregates multiple sources) IQAir combines: Official regional council monitors PurpleAir community sensors AirGradient sensors Other public/global data sources It’s often the most complete real-time view in NZ, especially if your town has no official station. View the map here → LAWA Air Quality (official NZ data + long-term trends) LAWA provides verified PM2.5 and PM10 readings where regional councils have monitors, plus: Recent hourly data Long-term and seasonal trends Annual exceedances of NZ standards Great for understanding typical patterns, coverage varies. View the map here → Indoor air-quality monitors Outdoor data doesn’t always reflect what’s happening inside your home.An indoor PM2.5 monitor helps you see: How much smoke is leaking in When levels rise How effective your purifier is This is especially useful in older NZ homes that naturally draw in outdoor air. We have a selection of Air Quality Monitors here → 4. Air Purifiers: The Most Effective Way to Reduce PM2.5 Indoors A HEPA air purifier is the most effective tool for lowering PM2.5 indoors during smoke events. Whether it’s from wildfires, woodburners, industrial fires, or long-range smoke drift. Why HEPA works best HEPA filters are extremely effective at physically trapping fine smoke particles. Their very fine weave and fibrous nature means particles big and small are captured and removed from the air. Most home ventilation systems cannot properly remove PM2.5 unless upgraded with a HEPA-grade filter, which normally isn't done as it restricts airflow significantly. What to look for HEPA filtration, H11/H12/H13 grades will be very effective High CADR / strong airflow No ionisers or plasma systems (they can create harmful byproducts) How to use your purifier During major smoke events: Run on medium–high Keep doors closed Focus on rooms you’re actively using A purifier can quickly bring PM2.5 under control even in older or draughty homes. 5. Do Carbon Filters Help? HEPA removes harmful particles. Carbon filters help with: Smoke odour VOCs from woodburners Lingering wildfire smells Fumes from industrial fires Carbon is optional for comfort, but HEPA is essential for safety. 6. Final Thoughts Smoke can impact New Zealand homes any time of year, whether from winter woodburners, wildfires, industrial incidents or far-travelled smoke. The most effective approach is: Keep smoke out Turn off systems that bring outdoor air inside Use a HEPA purifier to reduce PM2.5 Monitor air quality inside and out These simple steps help keep your indoor air healthier during smoke events. Our store contains a selection of effective and affordable air purifiers and air quality monitors designed to keep you safe from smoke.

We're well known for our breathtaking natural landscapes, often associated with clean air and an untouched environment. However, there are areas of the country where poor air quality issues are an unfortunate reality. Let's take a closer look at the causes of air pollution in NZ. Air Pollution: The Big Picture As per the latest LAWA Air Quality National Picture Summary, NZ has relatively good air quality overall. Yet, in some regions, people are exposed to higher levels of particulate matter, particularly during the winter months. This disparity arises due to several factors, such as weather conditions, geography, and the nature and volume of emissions present in each area. Winter Woes: Home Heating and Air Quality As we previously discussed in our blog on winter air quality issues, the lack of wind on colder winter days and the occurrence of inversion layers can trap particulate matter close to the ground, causing pollution levels to spike. Wood burners are popular in these areas, which emit particulate matter. The Role of Vehicles in Air Pollution Motor vehicles, especially those that are diesel-powered, are significant contributors to air pollution in NZ. They emit high amounts of pollutants such as nitrogen dioxide (NO2) and particulate matter. Factors like brake wear, tyre wear, and the presence of an older vehicle fleet compound the issue. Nature's Role in Air Quality At times, nature itself contributes to spikes in air pollution. Events like wildfires and occasional volcanic eruptions introduce large amounts of particulate matter and gases into the atmosphere, affecting local air quality. Insights from LAWA’s 2023 Summary According to the LAWA (Land Air Water Aotearoa) summary, in 2022, 42 of 60 monitored sites met the New Zealand standard for daily average PM10 concentrations. However, the monitoring of smaller particles (PM2.5) has revealed that these can exceed international guidelines more often than PM10. These tiny particles pose more significant health risks as they can lodge deep into our lungs and even reach the bloodstream. Through enhanced monitoring efforts, regional councils and unitary authorities aim to understand and manage air quality more effectively. Measures to Improve Air Quality As we gear up against winter cold, we can also protect ourselves from air pollution. Monitor the Air Quality Monitoring can help us make informed decisions about indoor stay times during poor air quality periods. LAWA has a great air quality dashboard which can tell you more about the trends in your area. For live air quality monitoring check out the aqicn website. It can also help to monitor your indoor air, we have affordable and high accuracy air quality monitors available on our website. Air Purifiers and Filters Quality air purifiers can remove harmful particulate matter from your home's air. Opt for purifiers with HEPA filters to remove PM2.5 particles. We provide a range of proven, affordable and effective air purifiers from Smart Air. Final Thoughts While New Zealand enjoys a reputation for clean air and a pristine environment, there is plenty of room for improvement. Armed with knowledge and understanding, we can better tackle the complexities of air pollution.

Air quality is an essential but often overlooked aspect of our well-being. In New Zealand, many remain unaware of how winter weather can profoundly affect the air we breathe. The Unseen Winter Culprit Winter air pollution in New Zealand is mainly shaped by weather patterns and heating choices. In the colder regions, while less common than previous years, we still see fireplaces being used for warmth. These emit particulate matter; tiny harmful particles into the air we breathe. Even though recently there have been tightened standards as far as emissions from these, they've focused on reducing the larger PM10 particles. The levels of PM2.5 seen in the air however, frequently exceed WHO recommendations. Inversion Layers: A Winter Phenomenon The New Zealand climate significantly influences air quality. In winter, many areas experience cold, still nights. These conditions, along with geographical features like mountains, create 'inversion layers'. This traps cold air and pollutants close to the ground, boosting harmful particle levels. We commonly see these occur in valleys and parts of Canterbury, Otago, Southland and Marlborough. Inversion layers occur when a layer of warm air sits on top of cooler air. This is the reverse of what we normally see where air gets cooler at higher elevations. This "lid" traps pollutants, contributing to higher PM10 and PM2.5 concentrations. PM10 and PM2.5 are particulate matter, or tiny particles in the air. PM10 particles are less than 10 micrometres in diameter, and PM2.5 are smaller, less than 2.5 micrometres. The tiny PM2.5 particles are concerning, as they penetrate deep into the lungs and bloodstream. Health Implications of Poor Air Quality Air quality influences our health. Both PM10 and PM2.5 pose health risks. The smaller PM2.5 particles, which can infiltrate our respiratory system, exacerbate conditions like asthma and COPD and can contribute to heart disease and lung cancer development over time. The World Health Organization states PM2.5 exposure can lead to respiratory and cardiovascular issues, hospital admissions, and mortality from cardiovascular and respiratory diseases and lung cancer. Understanding air quality's link to health is vital, especially for those in colder New Zealand regions, where winter pollution can be harmful. Pollution levels in these areas can reach unhealthy and even very unhealthy levels at times. Measures to Improve Air Quality As we gear up against winter cold, we can also protect ourselves from air pollution. Monitor the Air Quality Understanding the air quality in your area is important. In many countries checking the air quality is as common a task as checking the weather. Monitoring can help us make informed decisions about when to go outside and for how long during poor air quality periods. LAWA (Land Air Water Aotearoa) has a great air quality dashboard which can tell you more about the trends in your area. For live air quality monitoring check out the aqicn website. It can also help to monitor your indoor air, as outdoor pollutants can seep into your home. Personally, I found in my Christchurch home that during cold winter nights the air inside my home would often reach unhealthy levels due to the pollution. Want to check if the same happens to you? We have affordable and high accuracy air quality monitors available on our website. Air Purifiers and Filters Quality air purifiers can remove harmful particulate matter from your home's air. Opt for purifiers with HEPA filters to remove PM2.5 particles. We provide a range of proven, affordable and effective air purifiers from Smart Air. Clean Heating Cleaner heating options can improve air quality. If possible, consider shifting from wood burners to cleaner heat pump options. Wrapping up Awareness is the first step in enhancing our winter air quality. The more we understand, the better we can protect our health and communities. Stay informed, take action, and breathe easier this winter.