NZ Herald
  • Home
  • Latest news
  • Herald NOW
  • Video
  • New Zealand
  • Sport
  • World
  • Business
  • Entertainment
  • Podcasts
  • Quizzes
  • Opinion
  • Lifestyle
  • Travel
  • Viva
  • Weather

Subscriptions

  • Herald Premium
  • Viva Premium
  • The Listener
  • BusinessDesk

Sections

  • Latest news
  • New Zealand
    • All New Zealand
    • Crime
    • Politics
    • Education
    • Open Justice
    • Scam Update
  • Herald NOW
  • On The Up
  • World
    • All World
    • Australia
    • Asia
    • UK
    • United States
    • Middle East
    • Europe
    • Pacific
  • Business
    • All Business
    • MarketsSharesCurrencyCommoditiesStock TakesCrypto
    • Markets with Madison
    • Media Insider
    • Business analysis
    • Personal financeKiwiSaverInterest ratesTaxInvestment
    • EconomyInflationGDPOfficial cash rateEmployment
    • Small business
    • Business reportsMood of the BoardroomProject AucklandSustainable business and financeCapital markets reportAgribusiness reportInfrastructure reportDynamic business
    • Deloitte Top 200 Awards
    • CompaniesAged CareAgribusinessAirlinesBanking and financeConstructionEnergyFreight and logisticsHealthcareManufacturingMedia and MarketingRetailTelecommunicationsTourism
  • Opinion
    • All Opinion
    • Analysis
    • Editorials
    • Business analysis
    • Premium opinion
    • Letters to the editor
  • Politics
  • Sport
    • All Sport
    • OlympicsParalympics
    • RugbySuper RugbyNPCAll BlacksBlack FernsRugby sevensSchool rugby
    • CricketBlack CapsWhite Ferns
    • Racing
    • NetballSilver Ferns
    • LeagueWarriorsNRL
    • FootballWellington PhoenixAuckland FCAll WhitesFootball FernsEnglish Premier League
    • GolfNZ Open
    • MotorsportFormula 1
    • Boxing
    • UFC
    • BasketballNBABreakersTall BlacksTall Ferns
    • Tennis
    • Cycling
    • Athletics
    • SailingAmerica's CupSailGP
    • Rowing
  • Lifestyle
    • All Lifestyle
    • Viva - Food, fashion & beauty
    • Society Insider
    • Royals
    • Sex & relationships
    • Food & drinkRecipesRecipe collectionsRestaurant reviewsRestaurant bookings
    • Health & wellbeing
    • Fashion & beauty
    • Pets & animals
    • The Selection - Shop the trendsShop fashionShop beautyShop entertainmentShop giftsShop home & living
    • Milford's Investing Place
  • Entertainment
    • All Entertainment
    • TV
    • MoviesMovie reviews
    • MusicMusic reviews
    • BooksBook reviews
    • Culture
    • ReviewsBook reviewsMovie reviewsMusic reviewsRestaurant reviews
  • Travel
    • All Travel
    • News
    • New ZealandNorthlandAucklandWellingtonCanterburyOtago / QueenstownNelson-TasmanBest NZ beaches
    • International travelAustraliaPacific IslandsEuropeUKUSAAfricaAsia
    • Rail holidays
    • Cruise holidays
    • Ski holidays
    • Luxury travel
    • Adventure travel
  • Kāhu Māori news
  • Environment
    • All Environment
    • Our Green Future
  • Talanoa Pacific news
  • Property
    • All Property
    • Property Insider
    • Interest rates tracker
    • Residential property listings
    • Commercial property listings
  • Health
  • Technology
    • All Technology
    • AI
    • Social media
  • Rural
    • All Rural
    • Dairy farming
    • Sheep & beef farming
    • Horticulture
    • Animal health
    • Rural business
    • Rural life
    • Rural technology
    • Opinion
    • Audio & podcasts
  • Weather forecasts
    • All Weather forecasts
    • Kaitaia
    • Whangārei
    • Dargaville
    • Auckland
    • Thames
    • Tauranga
    • Hamilton
    • Whakatāne
    • Rotorua
    • Tokoroa
    • Te Kuiti
    • Taumaranui
    • Taupō
    • Gisborne
    • New Plymouth
    • Napier
    • Hastings
    • Dannevirke
    • Whanganui
    • Palmerston North
    • Levin
    • Paraparaumu
    • Masterton
    • Wellington
    • Motueka
    • Nelson
    • Blenheim
    • Westport
    • Reefton
    • Kaikōura
    • Greymouth
    • Hokitika
    • Christchurch
    • Ashburton
    • Timaru
    • Wānaka
    • Oamaru
    • Queenstown
    • Dunedin
    • Gore
    • Invercargill
  • Meet the journalists
  • Promotions & competitions
  • OneRoof property listings
  • Driven car news

Puzzles & Quizzes

  • Puzzles
    • All Puzzles
    • Sudoku
    • Code Cracker
    • Crosswords
    • Cryptic crossword
    • Wordsearch
  • Quizzes
    • All Quizzes
    • Morning quiz
    • Afternoon quiz
    • Sports quiz

Regions

  • Northland
    • All Northland
    • Far North
    • Kaitaia
    • Kerikeri
    • Kaikohe
    • Bay of Islands
    • Whangarei
    • Dargaville
    • Kaipara
    • Mangawhai
  • Auckland
  • Waikato
    • All Waikato
    • Hamilton
    • Coromandel & Hauraki
    • Matamata & Piako
    • Cambridge
    • Te Awamutu
    • Tokoroa & South Waikato
    • Taupō & Tūrangi
  • Bay of Plenty
    • All Bay of Plenty
    • Katikati
    • Tauranga
    • Mount Maunganui
    • Pāpāmoa
    • Te Puke
    • Whakatāne
  • Rotorua
  • Hawke's Bay
    • All Hawke's Bay
    • Napier
    • Hastings
    • Havelock North
    • Central Hawke's Bay
    • Wairoa
  • Taranaki
    • All Taranaki
    • Stratford
    • New Plymouth
    • Hāwera
  • Manawatū - Whanganui
    • All Manawatū - Whanganui
    • Whanganui
    • Palmerston North
    • Manawatū
    • Tararua
    • Horowhenua
  • Wellington
    • All Wellington
    • Kapiti
    • Wairarapa
    • Upper Hutt
    • Lower Hutt
  • Nelson & Tasman
    • All Nelson & Tasman
    • Motueka
    • Nelson
    • Tasman
  • Marlborough
  • West Coast
  • Canterbury
    • All Canterbury
    • Kaikōura
    • Christchurch
    • Ashburton
    • Timaru
  • Otago
    • All Otago
    • Oamaru
    • Dunedin
    • Balclutha
    • Alexandra
    • Queenstown
    • Wanaka
  • Southland
    • All Southland
    • Invercargill
    • Gore
    • Stewart Island
  • Gisborne

Media

  • Video
    • All Video
    • NZ news video
    • Herald NOW
    • Business news video
    • Politics news video
    • Sport video
    • World news video
    • Lifestyle video
    • Entertainment video
    • Travel video
    • Markets with Madison
    • Kea Kids news
  • Podcasts
    • All Podcasts
    • The Front Page
    • On the Tiles
    • Ask me Anything
    • The Little Things
  • Cartoons
  • Photo galleries
  • Today's Paper - E-editions
  • Photo sales
  • Classifieds

NZME Network

  • Advertise with NZME
  • OneRoof
  • Driven Car Guide
  • BusinessDesk
  • Newstalk ZB
  • Sunlive
  • ZM
  • The Hits
  • Coast
  • Radio Hauraki
  • The Alternative Commentary Collective
  • Gold
  • Flava
  • iHeart Radio
  • Hokonui
  • Radio Wanaka
  • iHeartCountry New Zealand
  • Restaurant Hub
  • NZME Events

SubscribeSign In
Advertisement
Advertise with NZME.
Home / New Zealand

<i>Chris de Freitas:</i> Unseen enemies in exhaust

19 Oct, 2006 05:07 AM4 mins to read

Subscribe to listen

Access to Herald Premium articles require a Premium subscription. Subscribe now to listen.
Already a subscriber?  Sign in here

Listening to articles is free for open-access content—explore other articles or learn more about text-to-speech.
‌
Save

    Share this article

Opinion by

The Herald has fallen into the same trap as many of the public and those in government: confusing greenhouse gas emissions with air quality.

An editorial this week noted that "Decisive action ... is required if the Government wishes to significantly improve air quality by reducing greenhouse gas emissions from vehicles." Testing exhaust emissions is an air-pollution issue. None of the main greenhouse gases are pollutants. The greenhouse gas emitted from motor vehicles is carbon dioxide.

All green plants live and grow by absorbing carbon dioxide from the atmosphere. Low levels of the gas in the Earth's atmosphere limit photosynthesis and thus plant growth.

It is not uncommon for greenhouse farmers to improve conditions for crop growth by injecting carbon dioxide into their greenhouses to levels almost three times the concentration outside.

There is good evidence to prove that increases in carbon dioxide concentration in the atmosphere over the past 70 years has enhanced plant and tree growth. It is frequently referred to as the great "greening of the Earth", a response to the many biological benefits provided by the ongoing rise in the atmosphere's carbon dioxide content.

When it comes to motor-vehicle exhaust emissions, many people are surprised to learn that a poorly tuned engine emits less carbon dioxide than when it is well-tuned. An engine that is running at a nearly ideal air/fuel ratio of 14.5:1 will show about 14.5 per cent carbon dioxide and 2.5 per cent oxygen in the exhaust.

As combustion efficiency decreases, the oxygen content in the exhaust rises and carbon dioxide falls. This translates to an over-rich or over-lean air/fuel ratio, poor compression, or an ignition problem.

Nevertheless it is true that driving a motor vehicle is the single most polluting thing that most of us do. It is also true that New Zealand is the only country in the OECD without effective vehicle-emission control standards and vehicle checks.

Hundreds of people in New Zealand die each year from air pollution and many more get sick from it. A study carried out for the Ministry of Transport five years ago estimated that 970 people over 30 die prematurely each year from exposure to air pollution and 436 of these deaths occur in the Auckland region. The source of most air pollution in the Auckland urban area is vehicle emissions.

So what is the Government's plan of action? The answer reflects the Government's naivete in dealing with this serious matter. From October 27, subjective assessment of exhaust emissions will be based on visual evidence of smoke during routine warrant-of-fitness tests.

This is consistent with the so called "10-second rule" that took effect in March 2001. The legislation allows police to issue a $150 fine to the driver of any motor vehicle that emits smoke for 10 seconds or more.

This will do little to improve air quality, because most motor-vehicle emissions are too small to see. In fact, the most dangerous ones are invisible. They include oxides of nitrogen, carbon monoxide and hydrocarbons as well as invisible particulate matter. Even well-tuned diesel engines cause invisible pollution in the form of particles smaller than 10-millionths of a metre. Called PM10, they are especially dangerous as they penetrate deep into the sensitive lining of the lungs.

Asthmatics and people with heart and lung disease are particularly susceptible. A high concentration of PM10 is associated with an increase in hospital admissions and lost work days.

Alert levels for PM10 are reached at all air-pollution monitoring sites in the Auckland region. PM2.5 is four times smaller than PM10 and is even more damaging to human health. There are regular breaches of guidelines for PM2.5. PM10 and PM2.5 have no "safe threshold".

Invisible nitrogen dioxide affects the respiratory system, irritates the lungs, worsens asthma and lowers resistance to infections. It is also suspected of forming carcinogens and mutagens in combination with other substances.

Another poison emitted by motor vehicles unchecked in New Zealand is carbon monoxide (CO). CO interferes with the blood's ability to absorb and circulate oxygen and can be lethal.

At certain concentrations CO can affect people with heart conditions such as angina and can impair co-ordination and concentration. Auckland's figures for CO have been compared with London's for the period 1998 to 2004. The results show that CO concentrations in London are declining steadily; this is not the case in Auckland.

It's ironic, given that, for so many years, the Government has been falling over itself to win over support for the Kyoto Protocol, a costly and highly debatable policy which most countries have decided not to implement.

* Chris de Freitas is an Associate Professor in the School of Geography, Geology and Environmental Science at the University of Auckland.

Advertisement
Advertise with NZME.
Advertisement
Advertise with NZME.
Save

    Share this article

Latest from New Zealand

Politics

Te Pāti Māori selects former broadcaster for Tāmaki Makaurau byelection

10 Jul 08:58 AM
New Zealand

Man sentenced for taking boy to secluded spot and photographing him without togs on

10 Jul 08:00 AM
New Zealand

State of emergency declared for Tasman region, severe weather warnings across NZ

10 Jul 07:04 AM

From early mornings to easy living

sponsored
Advertisement
Advertise with NZME.
Recommended for you
Te Pāti Māori selects former broadcaster for Tāmaki Makaurau byelection
Politics

Te Pāti Māori selects former broadcaster for Tāmaki Makaurau byelection

10 Jul 08:58 AM
France overhaul squad for second All Blacks test
All Blacks

France overhaul squad for second All Blacks test

10 Jul 08:13 AM
Man sentenced for taking boy to secluded spot and photographing him without togs on
New Zealand

Man sentenced for taking boy to secluded spot and photographing him without togs on

10 Jul 08:00 AM
Inside the world’s swankiest ski hotels
Travel

Inside the world’s swankiest ski hotels

10 Jul 08:00 AM
State of emergency declared for Tasman region, severe weather warnings across NZ
New Zealand

State of emergency declared for Tasman region, severe weather warnings across NZ

10 Jul 07:04 AM

Latest from New Zealand

Te Pāti Māori selects former broadcaster for Tāmaki Makaurau byelection

Te Pāti Māori selects former broadcaster for Tāmaki Makaurau byelection

10 Jul 08:58 AM

Move comes after MP Takutai Tarsh Kemp died last month.

Man sentenced for taking boy to secluded spot and photographing him without togs on

Man sentenced for taking boy to secluded spot and photographing him without togs on

10 Jul 08:00 AM
State of emergency declared for Tasman region, severe weather warnings across NZ

State of emergency declared for Tasman region, severe weather warnings across NZ

10 Jul 07:04 AM
‘Lock all your doors’: Neighbours recount gunman on loose after Hamilton homicide

‘Lock all your doors’: Neighbours recount gunman on loose after Hamilton homicide

10 Jul 07:00 AM
Solar bat monitors uncover secrets of Auckland’s night sky
sponsored

Solar bat monitors uncover secrets of Auckland’s night sky

NZ Herald
  • About NZ Herald
  • Meet the journalists
  • Newsletters
  • Classifieds
  • Help & support
  • Contact us
  • House rules
  • Privacy Policy
  • Terms of use
  • Competition terms & conditions
  • Our use of AI
Subscriber Services
  • NZ Herald e-editions
  • Daily puzzles & quizzes
  • Manage your digital subscription
  • Manage your print subscription
  • Subscribe to the NZ Herald newspaper
  • Subscribe to Herald Premium
  • Gift a subscription
  • Subscriber FAQs
  • Subscription terms & conditions
  • Promotions and subscriber benefits
NZME Network
  • The New Zealand Herald
  • The Northland Age
  • The Northern Advocate
  • Waikato Herald
  • Bay of Plenty Times
  • Rotorua Daily Post
  • Hawke's Bay Today
  • Whanganui Chronicle
  • Viva
  • NZ Listener
  • Newstalk ZB
  • BusinessDesk
  • OneRoof
  • Driven Car Guide
  • iHeart Radio
  • Restaurant Hub
NZME
  • About NZME
  • NZME careers
  • Advertise with NZME
  • Digital self-service advertising
  • Book your classified ad
  • Photo sales
  • NZME Events
  • © Copyright 2025 NZME Publishing Limited
TOP
search by queryly Advanced Search