Key Points | Report Card | Technical Information | Data
This page contains technical details on how and where we collect this information.
On this page: What this indicator is about, why we monitor carbon monoxide levels in air, where and how we collect the data, how this indicator is compiled, guidelines and standards, limitations , further indicator developments, when this indicator is updated, more information
What this indicator is about
Carbon monoxide is an indicator of poor air quality. It’s associated with areas of high-density housing and busy roads. Waikato Regional Council continuously measures carbon monoxide levels in Hamilton.
Why we monitor carbon monoxide levels in air
Carbon monoxide is a poisonous gas that is colourless, odourless and tasteless. Waikato Regional Council monitors carbon monoxide to determine people’s exposure to it in areas where the air quality is suspected to be poor.
Carbon monoxide is poisonous because it attaches to our red blood cells better than oxygen - reducing the blood’s ability to carry oxygen around the body. Low exposure to carbon monoxide causes headaches, dizziness and nausea.
High exposure to carbon monoxide (for example, high concentrations present in enclosed areas) causes loss of consciousness and death.
Where and how we collect the data
Waikato Regional Council measures carbon monoxide levels in Hamilton. We suspect Hamilton to be at risk from carbon monoxide because of the density of housing and levels of traffic.
Monitoring sites
Carbon monoxide is monitored in Hamilton at Waikato Regional Council's Peachgrove Road monitoring site. This is classified as a residential peak monitoring site in accordance with the Ministry for the Environment’s air quality monitoring site classifications.
Monitoring frequency
Carbon monoxide concentrations are measured continuously and are logged as 10 minute averages. Hourly and eight hour averages are derived from 10 minute data.
Monitoring history
Carbon monoxide monitoring commenced at the Peachgrove Road site in November 1997.
While data are collected continuously, several periods of missing data have occurred. The largest of these are:
- November 1 to December 22, 1998
- October 5 to November 17, 1999
- January 22 to February 13, 2001
- August 29 to September 16, 2002
- February 24 to March 19, 2003
- April 18 to May 18, 2003
- February 24 to March 18, 2004
- April 17 to May 17, 2004.
Measurement technique
Monitoring is carried out using an advanced pollution instrumentation (API) analyser. This is a continuous analyser that measures carbon monoxide concentrations using gas-correlation infra-red absorption.
Data are outputted as 1-hour averages. Hourly average data are not compiled if more than 15 per cent of the data for the period are missing.
How this indicator is compiled
Monitoring results are reported in relation to the proposed regional guideline, using the Ministry for the Environment air quality indicator reporting framework outlined in the table below. This framework is used to report on air quality for a range of contaminants relative to their respective guidelines.
Table 1: Ministry for the Environment categories for air quality
| Category |
Value relative to guideline |
Comment |
| Excellent |
Less than 10% of the guideline |
Of little concern |
| Good |
Between 10% and 33% of the guideline |
Peak measurements in this range are unlikely to affect air quality |
| Acceptable |
Between 33% and 66% of the guideline |
A broad category, where maximum values might be of concern in some sensitive locations but generally they are at a level which does not warrant dramatic action |
| Alert |
Between 66% and 100% of the guideline |
A warning level, which can lead to the guideline being exceeded if trends are not curbed |
| Action |
More than 100% of the guideline |
Exceeding the guideline is a cause for concern and warrants action if it occurs regularly |
Tables 2 and 3 show the percentage of times carbon monoxide levels fell into each category and the maximum level for the year of monitoring.
Table 2: 1998-2004 one hour carbon monoxide levels at Hamilton
| Year |
Categories |
99.9
%ile1 (mg/m3) |
Maximum value (mg/m3) |
Number of times levels exceeded the proposed regional guideline |
| Excellent |
Good |
Acceptable |
Alert |
Action |
| 1998 |
98% |
2% |
0% |
0% |
0% |
7 |
9 |
0 |
| 1999 |
99% |
1% |
0% |
0% |
0% |
4 |
7 |
0 |
| 2000 |
100% |
0% |
0% |
0% |
0% |
4 |
5 |
0 |
| 2001 |
98% |
2% |
0% |
0% |
0% |
8 |
9 |
0 |
| 2002 |
99% |
1% |
0% |
0% |
0% |
6 |
10 |
0 |
| 2003 |
99% |
1% |
0% |
0% |
0.0 |
6 |
7 |
0 |
| 2004 |
97% |
3% |
0% |
0% |
0% |
7 |
9 |
0 |
Table 3: 1998-2004 8-hour carbon monoxide levels at Hamilton
| Year |
Categories |
99.9
%ile1 (mg/m3) |
Maximum value (mg/m3) |
Number of times levels exceeded the proposed regional guideline |
| Excellent |
Good |
Acceptable |
Alert |
Action |
| 1998 |
84% |
16% |
1% |
0% |
0% |
5 |
5 |
0 |
| 1999 |
92% |
7% |
0% |
0% |
0% |
3 |
4 |
0 |
| 2000 |
97% |
3% |
0% |
0% |
0% |
2 |
3 |
0 |
| 2001 |
86% |
13% |
2% |
0% |
0% |
7 |
7 |
0 |
| 2002 |
88% |
12% |
0% |
0% |
0% |
4 |
5 |
0 |
| 2003 |
93% |
6% |
1% |
0% |
0.0 |
5 |
5 |
0 |
| 2004 |
84% |
14% |
1% |
0% |
0% |
6 |
7 |
0 |
Guidelines and standards
Waikato Regional Council uses the national ambient air quality guidelines for carbon monoxide, which are:
- 30 mg/m3 – one hour average.
- 10 mg/m3 – eight-hour average.
Limitations
Waikato Regional Council has carried out carbon monoxide monitoring in Hamilton only. Results from Hamilton suggest that carbon monoxide concentrations in other areas are unlikely to be of concern.
Further indicator developments
Carbon monoxide will be monitored again in Hamilton 2010.
When this indicator is updated
This indicator will be updated in 2011.
More information
Documents available from Waikato Regional Councli
You can order any of these documents from our library. Most documents will incur a charge.
Ministry for the Environment. 2000: Environmental Performance Indicators: monitoring and data management for air indicators: signposts for sustainability. EPI, Technical Paper No.60, Ministry for the Environment, June 2000, Wellington.
Noonan, M. 1997: Hamilton, Tokoroa and Te Kuiti – Home heating and motor vehicle emissions inventory. Waikato Regional Council, Hamilton.
Wilton, E . 2004: Air Quality Monitoring Report 2004 - Waikato Region. Report prepared for Waikato Regional Council. Waikato Regional Council, Hamilton.
Wilton, E . 2003: Air Quality Monitoring Report - Waikato Region. Report prepared for Waikato Regional Council. Waikato Regional Council, Hamilton
Wilton, E . 2002: Air Quality Monitoring Report – Waikato Region. Report prepared for Waikato Regional Council. Waikato Regional Council, Hamilton
Wilton, E. 2002: Hamilton, Tokoroa and Te Kuiti - Domestic Heating Emission Inventory 2001. Report prepared for Waikato Regional Council. Waikato Regional Council, Hamilton
Wilton, E. 2001: Taupo, Huntly, Putaruru and Matamata - Domestic Heating Emission Inventory. Report prepared for Waikato Regional Council. Waikato Regional Council, Hamilton.
Useful links
Contact person
Air Scientist - Resource Information Group, Waikato Regional Council
Quality control procedures
Waikato Regional Council, 1999: Environmental Monitoring Technical Manual. Waikato Regional Council, Hamilton. (unpublished).
Related indicators
Footnotes
- The 99.9 per cent value is the highest value recorded for 0.1 per cent of samples. Compared with the recorded maximum value this provides more information about extreme values.