Mid-season update

mid 2013
Based on the date of the season's  first high grass pollen day, on October 21 I said we could expect about 25 high and extreme grass pollen days by December 31.  A high day is one with an average of 50 or more grass pollen grains per cubic metre of air and our extreme days occur when the count is over 100.

So far this season there have been nine high days and one extreme grass pollen day.  By the same time last year there had been ten high and six extreme pollen days.

The dotted line in today's graph shows the average daily grass pollen count from 1996 onwards. November is clearly our worst month with the daily count mostly in the red zone (high and extreme). The solid line is this year's count and it's mostly in the blue low zone.

Thanks to good winter and spring rains, it's been a good season for grass growth.  The question is, why hasn't it been a far worse hay fever season?

It's no secret that November has been pretty cool. And in Melbourne that means southerly winds.

The pastures where our grass pollen mostly comes from are to our north and west.  Carrying that grass pollen into Melbourne needs warmer north/north-westerly winds. So we've had the wrong sorts of wind this year for a bad hay fever season.

The other thing today's graph shows is that the season really starts to tail off in December.

With luck it'll all be over by Christmas.


Fright Night - Happy Halloween

I was working in the lab late one night
When my eyes beheld a terrible sight
Down the microscope upon the slide
  Were devilish pollen grains out for a ride.

Halloween 2013

First high grass pollen day for 2013

Last Saturday (19 October) we had the first high grass pollen day for the 2013 season - Achooo!  Can this date tell us anything about the season ahead?

The graph shows the date of the first high grass pollen day for each season from 1996 to 2012, plotted against the total number of high and extreme grass pollen days for that season.

Remember that our high days are when the grass pollen count is 50 or more grass pollen grains per cubic metre of air, and our extreme days when there is 100 or more grass pollen grains.  Also, that our counting season starts on October 1 and finishes on December 31.

The graph shows that our earliest high grass pollen days are in early October and our latest in mid-November.  The line shows a relationship called a linear regression that attempts to explain the data points using a simple equation.  The line isn't a perfect explanation of the data but it's not a bad approximation either (for the technically minded, the R2 for the regression is 0.54).

So the earlier the first high day the worse the season and vice versa. 

The red dot shows October 19, the first high day for this season.  Based on this date we can expect about 25 high and extreme grass pollen days by December 31.

Put another way, that's about a third of the days left in the year.  Not our worst year but bad enough.

Scope: Pollen is an important substance, but can cause problems for those with allergies

SCOPE: Pollen is an important substance, but can cause problems for those with allergies

Pollen is an important substance produced by plants, but it can also cause problems for those of us who have allergies. Dr Ed Newbigin is a botanist from The University of Melbourne and he steps through the process of establishing a daily pollen count.


Pollen count record high

Pollen count levels are predicted to hit a record high this spring, as millions of hayfever sufferers stock up on tissues, pills and nasal sprays.

According to Professor Connie Katelaris from New South Wales Health it's difficult to completely avoid allergens.

However Professor Katelaris says there are practical measure that can be taken to lessen the impact of the symptoms.

Some simple tips for hayfever sufferers on how to reduce symptoms:

  1. If you're a gardener, plant a low-allergy garden close to your home
  2. Pillowslips can gather pollen all day, so dry them indoors
  3. Pets' coats can also collect pollen, so where possible keep them indoors
  4. Shower before you go to bed to wash the pollen from your hair
  5. If you're heading out, make sure you wear your sunglasses to protect your eyes

Professor Katelaris says there is a new pain-free form of immunotherapy for chronic sufferers that could help relieve symptoms.

"Immunotherapy works by changing a person's immune response, it changes an allergic response to a more pro-active response. So it's like a vaccination," Professor Katelaris said.

"New forms of therapy are perhaps just around the corner as we improve the forms of immunotherapy, making it more effective without needing to be on it for as long a period of time."

Dr John D'Arcy says it's best for sufferers to start on non-sedating antihistamines, as they tone down the immune response.

"If antihistamines don't work, try a prescription-only steroid spray. It can actually stop the immune reaction starting in the first place," Dr D'Arcy said.

"Saline is also a terrific treatment. A saline nasal spray is cheap and effective, with absolutely no side effects."