May 13, 2026
At Lyttelton Port, dusty products such as palm kernel extract (PKE), wheat and phosphate rock release particulate matter during unloading and transfer operations.
In 2023, LPC commissioned an independent year-long study by Mote Limited to understand whether bulk cargo unloading impacted local air quality.
The study involved deploying three particulate (PM10 ) dust monitors around the Inner Harbour, covering operations on Jetties 2, 3 and 7.
PM10 is the appropriate size range to capture emissions from these operations, distinguishing it from finer particles like PM2.5 , which are more associated with combustion.
The results showed that minor increases in particulate matter were only observed during some unloading events.
Importantly, all recorded PM10 levels remained below the World Health Organisation’s 24-hour and annual guideline thresholds.
The monitoring results have helped validate LPC’s dust mitigation processes, which include additional measures for handling products with a high dust risk.
For example:
• wheat showed the highest average PM10 concentrations during unloading, followed by superphosphate.
• PKE, despite its reputation for dustiness, showed lower PM10 levels than expected, possibly due to mitigation measures such as misting systems.
This granularity supports targeted operational controls such as:
• greater awareness and operational oversight
• wind-triggered shutdowns for high-risk products
• enhanced sweeping and misting protocols
• product-specific environmental procedures.
The data showed that the average 24-hour PM10 concentration is higher during winter.
These concentrations usually reach a maximum in the evening around 8pm and are almost certainly associated with domestic home heating in Lyttelton.
Similar patterns of variation are observed throughout New Zealand.
They are mainly due to emissions from domestic home heating, wood and coal fires, accumulating during cooler winter weather when thermal air inversions reduce the usual dispersion of emissions.
We continue to learn more about managing dust through understanding the products that pass through the Port and as new technology is developed.
While the wider dust monitoring project has finished, we will continue to monitor dust in one location in the Inner Harbour and refer to experts for advice.