Not to be sneezed at! Microscopic images reveal the invisible enemies faced by hayfever sufferers



With the hay fever season once more upon us, it's time to meet the enemy.

These extraordinary images reveal the microscopic grains of pollen that inflict misery on millions of Britons every year.

The pictures - captured using a scanning electron microscope - highlight the amazing variety of pollens that float invisibly through the air.

Pollen from a Forget-me-not petal. The grains are some of the smallest found measuring just 0.006mm.

Ball of fire: Acanthus pollen

The hay fever season normally begins in March or April when trees release the first pollen of the year.

Around four million people are vulnerable to tree pollen - particularly from birch trees. Ash, oak and London plane can also trigger unpleasant reactions.

The full hay fever season doesn't normally get going until May, when grasses start to pollinate. Almost 95 per cent of Britain's 15 million hay fever sufferers are allergic to grass pollen.

Pollen from an Alder: Using a vacuum chamber, Swiss photographer Martin Oeggerli is able to bounce an electron beam off the pollen grain's surface and map out perfectly its tiny features

Purple patch: The minuscule blue pollen of the violet forget-me-not

The late spring delayed the start of the hay fever season by a few weeks. However, the arrival of warm, sunny weather has begun to trigger runny noses, itching eyes and sniffles, particularly amoung hay fever sufferers the south of Britain.

Although the grains cause misery for millions, few people get a chance to see tree and grass pollen up close.

The grains are between 1.5 and 10 hundredths of a millimetres across - making them too small to see with the naked eye.

It may look like a pink UFO, but this is a pollen from the Persian silk tree Albizia. They are 15 times larger than those on a Forget-me-not

A grain of pollen from a willow tree, which has become stuck between flower petals. This one will die but others will be carried by bees to other plants

These images were captured by Swiss photographer Martin Oeggerli using a £250,000 scanning electron microscope stored in his cellar.

"People know a lot about pollen, what with so many hay fever sufferers during the summer," he said. "So it's funny to think that until now a lot of them will have never seen the grains before.

"Pollen is quite robust so you can put it into the microscope camera quite easily. The electron microscope works by scanning the item in question extremely slowly.

The pollen from a Malve flower: The grains are between 1.5 and 10 hundredths of a millimetres across - making them too small to see with the naked eye

Spot on: The pink-flecked green pollen grains of a Venus Flytrap

"My work is a very diversified mixture between science and art, with the ultimate aim to show a hidden but unimaginably beautiful realm of our planet.

"That's the major reason, why I go great lengths with preparation, scanning, coloration and printing techniques."

Capturing an image with an electron microscope is a time consuming and expensive process. The technique was invented in the 1930s, but only became widespread in the 1960s.

The pollen must first by coated with a layer of gold before it is fixed onto a slide. The slide is placed into a vacuum chamber and the air pumped out.

Pollen from a Pistia: Hayfever occurs because plants need to transfer pollen by wind and insect to fertilization and reproduce

Star of the show: Yellow geranium pollen on a starfish-shaped stamen

The slide must be in a vacuum to make sure that the electron beam used to scan its surface does not come into contact with any obstructions.

The beam is bounced of the surface, mapping out perfectly its tiny features.

The images come out in shades of grey, which means Dr Oeggerli has to colour all of his incredible pictures on a computer.

His collection includes the ball-like birch pollen - the main cause of hay fever in the spring. He has also captured pollen from alder, pine and willow.

Scaling the heights: Bromelia pollen

Brown study: Pollen of chaenomeles, a species of quince

The usual suspects: Pollen comes in many sizes. The pumpkin pollen grain in the middle is 0.2mm and just about visible to the naked eye

Hayfever is caused by people's immune system reacting to pollen.

Cells inside the nose and eyes release histamine and other chemicals when they come in contact with the grains, causing red eyes and a blocked nose.

It can be treated with antihistamine nose sprays, tablets, steroid nose sprays and even eye drops.

The problem occurs because plants need to transfer pollen by wind and insect to fertilization and reproduce.

Dr Oeggerli said: "The fact small pollen grains are distributed by the wind, while the larger ones are by insects, gives you an idea of the size we are dealing with here.

"To take ten images of one item will take about two days to do in total. Once the grains are scanned they are coloured-in by hand, it's a very time-consuming and artistic work."

Double trouble: Smooth pollen from the pine tree

At first glance they look like sea shells. But this is in fact pollen from a Lilly



