Air pollution significantly impairs pollination because butterflies and bees are unable to sniff out plants that depend on them, new research suggests.
This is the warning of University of Reading-led experts who assessed the impact of pollutants found in diesel fumes and ozone on the pollination of black mustard.
The study built on findings of the team’s previous work, which discovered that diesel fumes alter floral odours — which insects use to locate sources of pollen and nectar.
They found the presence of common ground-level air pollutants led to up to 90 per cent fewer flower visits and an overall pollination reduction of up to 31 per cent.
With insect pollination being vital to agriculture — delivering hundreds of billion pounds worth of economic value each year — the findings have broad impacts.
Pollination supports 8 per cent of the total value of agricultural food production and is vital to 70 per cent of crop species, including apples, cocoa and strawberries.
It is also essential to the lifecycles of a assorted species of wildflowers.
Diesel fumes are not the only challenges facing pollinating insects, the number of which have been experiencing ongoing declines.
In fact, a recent study estimated that around a quarter of all the world’s wild bee species have disappeared over the course of the last 30 years.
By leaving them unable to sniff out plants, Commonly-found air pollutants may be interfering with the ability of insects like bees and butterflies to pollinate flowers. Pictured: a bee pollinates a flower of a black mustard, the plant used by the researchers in the study
This is the warning from University of Reading-led researchers, who measured the impact of pollutants found in diesel fumes (pictured, stock) on the pollination of black mustard plants
They found the presence of common ground-level air pollutants led to up to 90 per cent fewer flower visits and an overall pollination reduction of up to 31 per cent. The study built on findings of the team’s previous work, which found that diesel fumes alter floral odours — which insects use to locate sources of pollen and nectar
‘The findings are worrying because these pollutants are commonly found in the air many of us breathe every day,’ said paper author and ecologist James Ryalls of the University of Reading.
‘We know that these pollutants are bad for our health — and the significant reductions we saw in pollinator numbers and activity shows that there are also clear implications for the natural ecosystems we depend on,’ he added.
‘We knew from our previous lab studies that diesel exhaust can have negative effects on insect pollinators,’ added co-author Robbie Girling, also of Reading.
‘But the impacts we found in the field were much more dramatic than we had expected,’ the agroecologist noted.
In the study, the team used a custom-built fumigation device to regulate the levels of nitrogen oxides (NOx) — polluting gases released by diesel exhaust fumes, as well as from power plants, industrial boilers and cement kilns — and ozone in an open field.
They kept the concentrations of these pollutants well below maximum average levels, and around 40–50 percent of the limits deemed safe for the environment by United States legislation.
The team then observed the impact this level of air pollution had, over the course of two summer field seasons, on the pollination of black mustard plants growing around the fumigator by locally-occurring, free-flying insects.
In the study, the team used a custom-built fumigation device to regulate the levels of nitrogen oxides (NOx) — polluting gases released by diesel exhaust fumes, as well as from power plants, industrial boilers and cement kilns — and ozone in an open field. Pictured: the experimental setup. Each octagon in the field was given a different mixture of NOx and ozone
The researchers found that plants located in the NOx- and ozone-polluted environment enjoyed 62–70 per cent fewer visits from pollinating insects.
This effect was seen across seven different pollinator groups including bees, butterflies, hoverflies and moths.
Moreover, these insects engaged in 83–90 per cent fewer individual flower visits, specifically, leading to an estimated reduction in pollination (as assessed by factors including seed yield) of around 14–31 per cent.
The researchers found that plants located in the NOx- and ozone-polluted environment enjoyed 62–70 per cent fewer visits from pollinating insects. This effect was seen across seven different pollinator groups including bees, butterflies, hoverflies and moths. Moreover, these insects engaged in 83–90 per cent fewer flower visits, specifically, leading to an estimated reduction in pollination (as assessed by factors including seed yield) of around 14–31 per cent
‘This truly cross-disciplinary work demonstrated very clearly how atmospheric pollutants negatively impact on pollination,’ said paper author and atmospheric scientist Christian Pfrang of the University of Birmingham.
This impact, he added, has ‘direct consequences for food production as well as the resilience of our natural environment.’
The full findings of the study were published in the journal Environmental Pollution.
‘This truly cross-disciplinary work demonstrated very clearly how atmospheric pollutants negatively impact on pollination,’ said paper author and atmospheric scientist Christian Pfrang of the University of Birmingham. Pictured: a close-up of one of the experimental area
Revealed: MailOnline dissects the impact greenhouse gases have on the planet – and what is being done to stop air pollution
Emissions
Carbon dioxide
Carbon dioxide (CO2) is one of the biggest contributors to global warming. After the gas is released into the atmosphere it stays there, making it difficult for heat to escape – and warming up the planet in the process.
It is primarily released from burning fossil fuels such as coal, oil and gas, as well as cement production.
The average monthly concentration of CO2 in the Earth’s atmosphere, as of April 2019, is 413 parts per million (ppm). Before the Industrial Revolution, the concentration was just 280 ppm.
CO2 concentration has fluctuated over the last 800,000 years between 180 to 280ppm, but has been vastly accelerated by pollution caused by humans.
Nitrogen dioxide
The gas nitrogen dioxide (NO2) comes from burning fossil fuels, car exhaust emissions and the use of nitrogen-based fertilisers used in agriculture.
Although there is far less NO2 in the atmosphere than CO2, it is between 200 and 300 times more effective at trapping heat.
Sulfur dioxide
Sulfur dioxide (SO2) also primarily comes from fossil fuel burning, but can also be released from car exhausts.
SO2 can react with water, oxygen and other chemicals in the atmosphere to cause acid rain.
Carbon monoxide
Carbon monoxide (CO) is an indirect greenhouse gas as it reacts with hydroxyl radicals, removing them. Hydroxyl radicals reduce the lifetime of carbon dioxide and other greenhouse gases.
Particulates
What is particulate matter?
Particulate matter refers to tiny parts of solids or liquid materials in the air.
Some are visible, such as dust, whereas others cannot be seen by the naked eye.
Materials such as metals, microplastics, soil and chemicals can be in particulate matter.
Particulate matter (or PM) is described in micrometres. The two main ones mentioned in reports and studies are PM10 (less than 10 micrometres) and PM2.5 (less than 2.5 micrometres).
Air pollution comes from burning fossil fuels, cars, cement making and agriculture
Scientists measure the rate of particulates in the air by cubic metre.
Particulate matter is sent into the air by a number of processes including burning fossil fuels, driving cars and steel making.
Why are particulates dangerous?
Particulates are dangerous because those less than 10 micrometres in diameter can get deep into your lungs, or even pass into your bloodstream. Particulates are found in higher concentrations in urban areas, particularly along main roads.
Health impact
What sort of health problems can pollution cause?
According to the World Health Organization, a third of deaths from stroke, lung cancer and heart disease can be linked to air pollution.
Some of the effects of air pollution on the body are not understood, but pollution may increase inflammation which narrows the arteries leading to heart attacks or strokes.
As well as this, almost one in 10 lung cancer cases in the UK are caused by air pollution.
Particulates find their way into the lungs and get lodged there, causing inflammation and damage. As well as this, some chemicals in particulates that make their way into the body can cause cancer.
Deaths from pollution
Around seven million people die prematurely because of air pollution every year. Pollution can cause a number of issues including asthma attacks, strokes, various cancers and cardiovascular problems.
Asthma triggers
Air pollution can cause problems for asthma sufferers for a number of reasons. Pollutants in traffic fumes can irritate the airways, and particulates can get into your lungs and throat and make these areas inflamed.
Problems in pregnancy
Women exposed to air pollution before getting pregnant are nearly 20 per cent more likely to have babies with birth defects, research suggested in January 2018.
Living within 3.1 miles (5km) of a highly-polluted area one month before conceiving makes women more likely to give birth to babies with defects such as cleft palates or lips, a study by University of Cincinnati found.
For every 0.01mg/m3 increase in fine air particles, birth defects rise by 19 per cent, the research adds.
Previous research suggests this causes birth defects as a result of women suffering inflammation and ‘internal stress’.
What is being done to tackle air pollution?
Paris agreement on climate change
The Paris Agreement, which was first signed in 2015, is an international agreement to control and limit climate change.
It hopes to hold the increase in the global average temperature to below 2°C (3.6ºF) ‘and to pursue efforts to limit the temperature increase to 1.5°C (2.7°F)’.
Carbon neutral by 2050
The UK government has announced plans to make the country carbon neutral by 2050.
They plan to do this by planting more trees and by installing ‘carbon capture’ technology at the source of the pollution.
Some critics are worried that this first option will be used by the government to export its carbon offsetting to other countries.
International carbon credits let nations continue emitting carbon while paying for trees to be planted elsewhere, balancing out their emissions.
No new petrol or diesel vehicles by 2040
In 2017, the UK government announced the sale of new petrol and diesel cars would be banned by 2040.
However, MPs on the climate change committee have urged the government to bring the ban forward to 2030, as by then they will have an equivalent range and price.
The Paris Agreement, which was first signed in 2015, is an international agreement to control and limit climate change. Pictured: air pollution over Paris in 2019.
Norway’s electric car subsidies
The speedy electrification of Norway’s automotive fleet is attributed mainly to generous state subsidies. Electric cars are almost entirely exempt from the heavy taxes imposed on petrol and diesel cars, which makes them competitively priced.
A VW Golf with a standard combustion engine costs nearly 334,000 kroner (34,500 euros, $38,600), while its electric cousin the e-Golf costs 326,000 kroner thanks to a lower tax quotient.
Criticisms of inaction on climate change
The Committee on Climate Change (CCC) has said there is a ‘shocking’ lack of Government preparation for the risks to the country from climate change.
The committee assessed 33 areas where the risks of climate change had to be addressed – from flood resilience of properties to impacts on farmland and supply chains – and found no real progress in any of them.
The UK is not prepared for 2°C of warming, the level at which countries have pledged to curb temperature rises, let alone a 4°C rise, which is possible if greenhouse gases are not cut globally, the committee said.
It added that cities need more green spaces to stop the urban ‘heat island’ effect, and to prevent floods by soaking up heavy rainfall.
Advertisement
