Original article, published 30 May 2015

TRANS fats are poised to be all but banned from food in the US. That is good news, and not just for Americans. It sends a strong message to the UK and other countries that lack regulation, despite overwhelming evidence that .

“There is overwhelming evidence that industrial trans fats raise the risk of heart disease and strokes”

Admittedly, these fats present a challenge to regulators, but not enough to prevent action that could stop many early deaths.

Chemically speaking, they are types of unsaturated fatty acid. Such fats occur in two structural forms – known as cis and trans – that affect their properties. Trans fats, which are a broad family, tend to be solid at room temperature, more akin to saturated fats. Some are bad for you, others are harmless, and one is beneficial – in milk, butter, cream and cheese. Indeed, trans fats are in all fats from ruminants, but there doesn’t seem to be a link between natural versions and ill health.

Health problems only arise from those made industrially, for example by partial hydrogenation of unsaturated oil. The resulting oil – often cited as “hydrogenated vegetable oil” – pretty much vanished from packaged-food ingredient lists as evidence of ill effects grew. Effectively banning this oil from all food, as the US looks set to do, would tackle to this trend. Fortunately, industrial and natural trans fats can easily be told apart.

But there are complications. Industrial trans fats can also form at raised temperatures. The hotter the plant runs, and the longer the oil is heated, the more trans fat is produced. In a well-run plant, this can be kept to 1 per cent. But in a badly run one, it could reach an unacceptably high 5 per cent. For many consumers, this is probably now the main source of industrial trans fats. So regulators should make sure that all oil processors achieve very low levels of them. Ultimately, we need to find out which specific trans fats cause serious health damage, so we can address them directly. As ever, more research is needed.

Still, we know quite enough to begin regulating industrial trans fats right now, improving the nation’s health and preventing countless premature deaths.

This article appeared in print under the headline “Time to tame a killer”

“We have found water vole burrows dug up by rats to eat the young, and we
have seen water vole corpses showing signs of rat predation,” says Rob Strachan
of Oxford University’s zoology department. “Rats will also overpower adult water
voles and kill them. We have recorded many instances of water vole decline or
extinction following the arrival of rats in an area.”

Strachan’s radio tracking experiments have also shown that, after rats
colonise an area, water voles alter their behaviour to avoid rats. Water voles
are normally active day and night on a 4-hour cycle. But after the arrival of
rats, which are mainly nocturnal, the voles hardly go out at night and only go
foraging during the day, limiting their ability to gather food.

Water voles in lowland Britain are now largely confined to rivers, suburban
areas and canals, says Alastair Driver of the Environment Agency. “They are
increasingly being squeezed into the same pockets of land as brown rats and
unfortunately the rats are getting the better of them.”

Dutch elm disease is caused by a fungus carried by Scotylus beetles,
which burrow beneath the bark of trees. Since the 1960s, the disease has killed
more than 80 per cent of elms in Britain. Clive Brasier of the Forestry
Commission Research Agency at Alice Holt in Hampshire warns that a “swarm” of
new forms of the fungus could evolve over the next few decades.

Ophiostoma ulmi, the original fungus, spread from Europe to North
America and Central Asia in the 1920s and 1930s. But in the 1940s, a more
virulent species, O. novo-ulmi, began to take over. A North American form of
O. novo-ulmi spread from the southern Great Lakes and reached Western
Europe in the 1960s in imported timber. At the same time, a European form spread
west from the Moldova-Ukraine region.

Now the two forms have met in Central Europe (see Map). The hybrids
occasionally produced when different fungal forms interbreed can be weak and
transient, but they can still act as “genetic bridges”, transferring genes
between the two parent forms. In particular, Brasier fears that they might allow
an exchange of genes governing vegetative compatibility, known as vc
genes.

A promising approach being developed to fight the disease relies on viruses
called d-factors (żěè¶ĚĘÓƵ, 15 February 1997, p 26). These spread
from fungus to fungus when the threads of two separate fungi fuse. However,
threads can fuse only if both fungi have the same vc genes. If they
have different ones, the d-factors cannot spread.

Hybridisation may have helped O. novo-ulmi to survive a virus
outbreak that checked the spread of O. ulmi in the 1940s. According to
Brasier, O. novo-ulmi appears to have gained new vc genes from
O. ulmi at that time. These genes allowed it to diversify into numerous
vc types and resist the spread of the viruses.

History may repeat itself in the current wave of hybridisation between the
two subspecies of O. novo-ulmi. “They may be better able to resist the
spread of viruses—and this is one of the main ways in which the disease
may otherwise go into spontaneous remission,” says Brasier.

In the case of alder blight—another fungal disease that attacks
trees—hybridisation led to the development of a new pathogen (New
żěè¶ĚĘÓƵ, 15 May 1999, p 7). Brasier points out that uncertainty over how
the Dutch elm fungus will develop makes breeding disease-resistant elms very
difficult.

In a new report commissioned by English Heritage, the agency responsible for
conserving historic buildings, John Letts of the University of Reading describes
how dry thatch buried under as much as 2 metres of later material is protected
from insect and fungal attack by soot and tar from fires.

“This smoke-blackened material is often perfectly preserved with fingerprint
quality DNA,” he says. “If you’re used to working with half-decayed samples from
archaeological digs, it’s amazing to see all the varieties of cereal and the
weeds they grew with exactly as they were taken from the field.”

Of the 325 known buildings with smoke-blackened thatch, 300 are in Devon.
Letts says that Devon’s thatchers attached battens to rafters with wooden pegs,
which have lasted better than the iron nails used elsewhere. This meant that the
lower layers of thatch never needed to be replaced.

But Letts warns that this research resource could be lost as commercial
thatching companies adopt new methods. Rather than attach thatch to existing
base coats, they prefer to throw away the original material and nail new
thatching—usually water reed rather than the traditional wheat
straw—directly to the rafters.

Think again. The application was made, not by a mobile phone company, but by
the University of Oxford on behalf of its ecologists and zoologists. The
university was bequeathed the Wytham Estate in 1943, and allows its scientists
to run the 400 or so hectares of woods as an biological research site. The woods
are a site of special scientific interest not because they are stuffed with rare
species (there are none), but because of the importance of the work that goes on
there.

The masts, moreover, are not intended for vulgar commercial gain, but to
track the movements of wild animals. No longer will eager young researchers have
to rampage through the woods at night with radio tracking devices to follow a
single badger, nor get up at the crack of dawn day after day to watch the
feeding habits of great tits, unable to distinguish one bird from another in the
weak light.

Instead, the radio masts, which are spaced 200 metres apart in a hexagonal
grid that spans the woods and the nearby farmland, could simultaneously track
thousands of animals fitted with tiny radio tags, day and night for years on
end. And it would be possible to study their movements in relation to each
other—great tits compared with sparrowhawks, badgers with hedgehogs,
weasels with field mice—to build up a complete picture of how an ecosystem
functions across many levels of the food chain.

The masts are only a small part of the overall WYTENET project, which aims to
turn Wytham Woods and its surrounds into a vast living laboratory. The woods are
to be wired up with power and data cables, which will run along existing rides.
These will then be linked to the masts, to weather and air quality monitoring
stations, to video cameras and other experiments, so that real-time data can be
fed back to remote computers and observers.

According to Will Cresswell of the university’s zoology department, whose
plan it is, the equipment would finally bring ecological data gathering up to
speed with modern data handling, giving ecology a new rigour and solidity and
putting it well on the way to becoming a truly predictive—as opposed to
merely descriptive—science.

Wytham Woods is already one of the world’s foremost ecological research
sites, having inspired more than 700 research papers—many of which form
part of the foundations of contemporary ecology. Cresswell’s plan would carry
the tradition forward and ensure Wytham’s (and Oxford’s) place at the cutting
edge of ecology into the 21st century.

In response to the villagers’ concerns, Cresswell is proposing to conceal
more of the masts within woodland and clumps of trees, use existing buildings
and telegraph poles, and do without some altogether. But the mood in Wytham
village remains hostile. Yes, residents appreciate that the scientific work is
important—but say that only an “overwhelming benefit to humanity” could
justify the project and its intrusion into Oxford’s green belt.

But to my way of thinking, the real environmentalists in this debate are the
ecologists. Their work on badgers could remove the need for the Ministry of
Agriculture’s cruel and costly badger cull, for example. We might discover
whether magpies really do wipe out songbirds, or whether the effect is
insignificant compared to the impact of modern farming. And we would be able to
quantify the effects of climate change and air pollution on a range of
ecosystems.

Wytham residents should ask, if the masts are refused planning permission,
then what? The work will surely be carried out elsewhere, and Wytham Woods could
lose its position as a world-class research site. The university’s cash-hungry
land managers would take over from the scientists and in all probability turn
the woods over to commercial forestry, deer stalking and pheasant rearing. No
radio masts perhaps, but rather chainsaws, timber trucks, rifles and shotguns.
Give me the scientists—radio masts included— any day.

A study by Ian Newton and colleagues at the Institute of Terrestrial Ecology
(ITE) in Monk’s Wood, Huntingdon, shows that the proportion of barn owls found
with anticoagulant rodenticides in their livers increased from 5 per cent in
1983-4 to 36 per cent in 1995-6. The figures are based on autopsies of 717 dead
barn owls found all over Britain over the period. About half of them were killed
by cars. In the same study, Richard Shore of the ITE found that 9 out of 29 dead
polecats collected between 1992 and 1994 contained rat poison. The findings will
be published later this year in Advances in Vertebrate Pest Management.

The rodenticides had killed only 5 per cent of the poisoned owls, and none of
the polecats. But the authors stress that the true mortality may be higher. They
say that when animals succumb to the poisons they become lethargic, and tend to
settle and die in woodland or some other concealed place where they are unlikely
to be found.

Ken Wildey of the agriculture ministry’s Central Science Laboratory in York
warns that rodenticide-resistant rats and mice are a threat to many species,
from domestic dogs and cats to foxes, weasels, stoats and birds of prey. It is a
problem in many countries. “Resistance is rising worldwide,” says Newton.

The first anticoagulant poisons, which work by knocking out the blood’s
clotting mechanism, were introduced in the 1950s. They accumulate in a rodent’s
body until a lethal dose is reached and the animal dies of internal bleeding.
But most rats are now resistant to first-generation anticoagulants such as
warfarin. Many are also resistant to the second-generation poisons such as
difenacoum and bromadialone, which are more toxic. These chemicals also stay in
the body longer, making it more likely that rodents will accumulate enough of
these chemicals to poison predators.

The threat to rare birds of prey is especially worrying. Out of 10 fledgling
red kites that left their nests last year in the Midlands, seven died. An
autopsy on the only corpse that was recovered showed that it had been poisoned
by bromadialone after eating a rodent. In May, an adult red kite in the Chiltern
Hills, northwest of London, was killed by brodifacoum, an anticoagulant so toxic
that it is only licensed in Britain for indoor use. Another adult kite found
dead last November in the Chilterns is also thought to have been poisoned.

“We think this is potentially a huge problem,” says Ian Carter, who leads the
red kite recovery programme run by English Nature, the government’s conservation
agency. “Kites are scavengers, so they will be selecting dead or dying prey and
they are more likely to eat rats with high rodenticide loadings than barn owls,
which take live prey.”

Adrian Meyer, a rodent control consultant based in Newbury, Berkshire, sees
no easy way out. “In some areas, rodenticide resistance has got to the point
where the poisons licensed for outdoor use no longer work, and it is only human
nature to use something else that does work,” he says. Meyer claims that the
Ministry of Agriculture, Fisheries and Food appears to have no coherent strategy
to deal with the resistance problem.

The problem was highlighted at the British Crop Protection Conference in Brighton last week by Ken Wildey of the Ministry of Agriculture, Fisheries and Food’s Central Science Laboratory in York. Wildey’s team studied grain from 279 commercial stores. Eighty-one per cent of the grain stores contained mites and 27 per cent contained beetles. The researchers have also studied 567 cereal-based food products, including flour, bread, breakfast cereals and biscuits. Of these foods, 21 per cent contained mites, which came from a total of 24 species.

The technique used to sample the mites from food kills the creatures, so the researchers don’t know which of the foods contained living mites. But even dead mites can trigger allergic reactions in sensitised people, if there are enough of them. One product—a dried rusk baby food—contained 20 000 mites per kilogram.

Wildey believes the problem is escalating because of resistance to pirimithos-methyl and other organophosphate pesticides. A quarter of the populations of sawtoothed grain beetles (Oryzaephilus surinamensis) isolated from grain stores showed some resistance to organophosphates. And 71 per cent of populations of Acarus siro, the most common mite in grain stores, survived 14 days of exposure to pirimithos-methyl at twice the recommended dose. Every single population of another species, Tyrophagus putrescentiae, was similarly resistant. “We have also found cross-resistance, with a number of mite strains resistant to all approved grain protectants,” says Wildey. “This may well result in a higher risk of contamination of foodstuffs by mites.”

Wildey fears a “total breakdown of chemical control options”. But pesticides aren’t the only option. Mites die if the moisture content of grain falls below 15 per cent, and most beetles are unable to breed below 15 °C. Adjusting the conditions under which grain is stored and reducing treatment with organophosphates would also reduce consumers’ exposure to pesticide residues in food.

But 90 per cent of commercial grain stores in Britain rely on organophosphates. Peter Beaumont, director of the Pesticides Trust in London, argues that the government’s Advisory Committee on Pesticides should revoke licences allowing grain stores to use organophosphate.

The real problem may lie elsewhere, however. Robin Appel, who runs a grain store that doesn’t use organophosphates in Waltham Chase, Hampshire, says that farmers routinely treat grain with the pesticides. “Farmers think they have got mites contained but they are actually feeding live mites into the human food chain,” he says. “What they have to do is cool and dry their grain much more rapidly.”

The survey, also sponsored by the UN Economic Commission for Europe, claims
that air pollution, fungi, drought and insect pests are to blame, though the
causes differ from country to country. The authors draw attention to the role of
air pollution, which can cause acid rain, disrupting the nutrient balance in
poor soils by leaching out minerals and enhancing the concentration of nitrates.
This encourages the growth of leaves that are more delicate and more susceptible
to frost and insects.

The survey found that oak trees suffered most on soils that had nutrient
imbalances, such as those affected by pollution. But the worst declines were in
northern Spain and southwest France, where there is relatively little air
pollution—and nobody knows why.

John Gibbs of Britain’s Forestry Commission Research Agency in Farnham,
Surrey, says that oaks have declined in large numbers across Europe several
times before and that it is something of a mystery. “We are looking at a range
of factors that have not yet been fully studied to see if there is any kind of
common thread,” he says.

ALL it takes is a beetle in a wooden packing case, a worm in an apple, or a
seed in the mud on your boot when you fly off on holiday, and a new organism has
leapt a continent. One in ten introduced organisms will thrive in their new
environment, and one in ten of those will be a problem.

We find it hard to imagine the effectiveness of the natural barriers that
existed until a few centuries ago between islands, continents, lakes, rivers and
seas, or lands divided by deserts and mountains. It was this isolation, in some
cases enduring since the break up of the Pangæa super-continent 240 million
years ago, that gave rise to unique, distinct ecosystems. Now, millions of years
of biological quarantine have come to a sudden end.

What happened after that unplanned full stop is the tale told by Chris Bright
of the Worldwatch Institute in Washington DC in his timely book Life Out of
Bounds. His message is stark: “At a frenetic and ever-increasing pace, the
global economy is merging the world’s ecosystems, smearing them into each other.
We are in the throes of a vast and little noticed biotic upheaval.” In
painstaking detail, he shows how the continents and the seas are coming together
as ecological entities. And he points out that this turmoil is reaching levels
of disturbance that no actual meeting of rock or water could possibly achieve.
And within the landmasses, island ecologies—a mountain range within a
desert, for example—are suffering. “Bio-invasion,” he points out, “is
perhaps the only category of environmental degradation that can corrode
virtually every level of biological organisation.”

So just how deep is the impact of this “bioinvasion”? In the US, between 5
and 25 per cent of flora in nature reserves are exotic, and more than a third of
all endangered species are under pressure from introduced exotics. Even such a
diverse ecosystem as the Everglades of Florida, with between 60 and 80 plant
species, has succumbed to a single invader. Dense thickets of the Australian
melaleuca tree have taken over the lush region, producing a near
monoculture.

Then there are the arable weeds, whose seeds have been sown into soils the
world over mixed with those of crops. And, as Bright reveals, the problem isn’t
just plants. The ecology of the Great Lakes suffered a blow, for example, when
the Caspian Sea’s zebra mussel arrived, carried in the bilges of ships as
ballast water. It is now busily wiping out native mussels, blocking up intake
pipes and filtering the lake water clean of the phytoplankton needed for many a
local organism to survive.

And the damage doesn’t stop there: the zebra mussel also concentrates
organochlorine pesticides from sediments, polluting any predators. In Lake Erie
alone it may have wiped $400 million off the fish catch. This mussel also
clogs up cooling water pipes in at least a dozen nuclear plants in the US,
costing each plant nearly $1 million a year to keep them under
control.

Bright totals up the cost of the exotics’ arrival to the US as a whole. In
1993, for example, the Office of Technology Assessment estimated the economic
cost of 79 major bioinvasions at $97 billion. And that doesn’t take into
account financial immeasurables such as the loss of more than two-thirds of
American fish to extinction in the past century because of the march of the
exotics.

And if North America is so vulnerable to alien invasion, how much more so are
small islands such as Mauritius or the Galápagos? Greater landmasses such
as Madagascar, New Zealand and Australia are not protected by their size. They,
too, are islands under threat. Hawaii is an extreme example. The natural rate at
which new insects arrive on these islands has multiplied a millionfold. Exotic
predators, competitors or diseases threaten 95 per cent of the islands’
endangered species.

We are now in the firing line because human diseases and their carriers are
also on the move. These have travelled with people and their animals for
hundreds of years. Bubonic plague travelled the Silk Route from Asia to Europe
in fleas on rats. Now the Asian tiger mosquito, whose bite carries dengue fever,
is travelling the world in shipments of used tyres. It has reached the US,
Brazil, southern Europe, Nigeria, New Zealand and Australia.

But the biggest factor when it comes to disease remains humans: the wealthy
make about 500 million international flights a year and the poor, the refugees
and people displaced by war or famine, of whom 100 million a year may be
crossing international borders. HIV, cholera, yellow fever, drug-resistant
malaria and tuberculosis travel easily via infected people.

And beyond that lurk other pests and pathogens of crops and
livestock—70 000 and rising. Take the potato blight fungus, which is
destroying about 20 per cent of the world’s potato crop. Or the tiny sap-sucking
tobacco whitefly, which has spread all over the world from Central Asia. It
carries about 60 plant viruses, has acquired resistance to many insecticides and
has led to 1 million hectares of land being abandoned in South America
alone.

Bright gives a searing example: over a few days in June 1993, a complex of
viruses, protozoa and bacteria wiped out nearly all of China’s shrimp industry.
Back in Hawaii, alien poxes from alien birds are passed on by alien mosquitoes
to kill native birds, while pineapple plantations (themselves an introduction)
are damaged by a wilt disease carried by South American mealybugs that are
milked and tended by African ants. And on Africa’s Lake Victoria, the Amazonian
water hyacinth has been helped in its takeover by the Nile perch.

Water hyacinths may yet be defeated by the introduction of insects from its
native environment that eat its shoots. This approach may work, as it did with
the South American water fern that had taken over Papua New Guinea’s Sepik River
bt 1990. But it may not.

Bright points out the dangerous alternative in his tale of Micronesia, where
monitor lizards were imported into sugar plantations to control rats eating the
crop. The large lizards took a liking to domestic poultry, so someone had the
bright idea of bring in cane toads to divert the lizards. It was a disaster.
Poisons on the cane toad skins killed the lizards, leading to an explosion in a
beetle pest of coconut trees, which the lizards had also been eating. Cats, dogs
and pigs ate the toads. All were poisoned, leading to a huge increase in numbers
of rats and of giant African snails. Did it stop here? No, someone introduced
another biological control: a flatworm to prey on the giant snails. The flatworm
spread across Oceania eating out the diverse native snails.

Incredibly, the lesson that Bright makes so plain has still not been learnt.
To alleviate fuel shortages in poor parts of the world, people who should know
better are advocating bringing in exotic “wonder trees” with a long record as
invasive pests. So they are promoting species of Prosopis,
Mimosa and Acacia.

So what is being done? Bright reveals that one of the barriers to action is
that despite the monumental cost of bioinvasions, they are “not a conceptual
category that figures in economic analysis”. This means that these costs are
ignored or sidelined. International law is weak: indeed, World Trade
Organisation rules forbid states from taking pre-emptive measures to prevent
pest invasions, if these would restrict the flow of goods.

It is high time, Bright argues, that the global community began to take the
problem seriously. Get accountants to count this collateral cost of growing
world trade. Remind environmental activists that genetically intact organisms in
the wrong place can be just as disruptive as GMOs ——and often
considerably more.