Question
Zone 6a, Harrisonburg, VA (in the Shenandoah Valley
    How dangerous is it to the environment to use sprays on roses?  I am giving a talk on "Why Spray" and I would like to put into perspective what damage is done by sprays as opposed to damage to the environment by driving your car to the grocery store!  Does this make sense?  
    I have 60 rose bushes and spray weekly, using one gallon of spray (with 5 or 6 fungicides and insecticides mixed) each time I spray.  Thanks for taking the time to answer this.  Sincerely, Rachel Hollis

Answer
Good idea for a talk. The secret to not having to spray roses is to only plant those which are disease resistant. Many of the newer roses are. It is the older cultivars that have been in commerce so long that they have lost all their good points because of constant budding. If a gardener lives in an area that gets a lot of rain in the spring and generally has a wet type of climate, the changes are very good that they will get more fungus dieases than a gardener in a dry climate. The reason that gardeners use sprays is because they want picture perfect roses which is not unreasonable but if you have to constantly spray a rose bush then you are definately growing the wrong cultivar for your area.
Simple fungicides don't damage the envirionment all that much but what happens is that roses get immuned to a certain brand and so you have to move up to a stronger and different fungicide. Fungicides will cause lung problems if you breathe them in as they are like a sulphur gas. To be completley safe one has to suit up like the people looking for the anthrax virus! Not an attractive picture in a flower garden.
The insecticides are the ones that definately effect the  invirionment. Insecticides should only be used when you see bugs, not as a routine spray. If you kill the bad guys you are also killing the good ones. When a bird eats a bug that has been sprayed with a insecticide it will either weaken the bird or kill it. Bees cannot tolerate any sprays and will be killed by only a small amount. This also goes for butterflies and any other insect that could eat the bad ones.
Driving a car releases the exhaust into the air and in some measure it is diluted. An insecticide is far reaching because it upsets the balance. An example is birds eat the poisoned bugs, if they don't die, the eggs are sterile or don't hatch and animals that eat birds are also made sick by the spray. Bees are needed for polination and if they get spray on them then that reduces their number. If an insect survives a spray, you now have created a super bug which now needs a stronger, nastier secticide. The insecticide for mites is a very nasty one( mites are tiny and can hide in petals) and is very toxic to humans. I realize that people who have Japanese beetles won't be pleased with a non insecticide view. One also has to study the enemy and learn how the insect lives and reproduces and also just how much damage can one accept.
Why spray?  Itis so much easier to simply spray a plant than study the insect and take time to control them.
Spraying is no different then taking antibiotics for a sniffle instead of using them for a more serious sickness. There is documented proof that people are getting immuned to drugs that used to save their lives.
By the way, the worst poluter is the man that puts on a weed killer on the lawn every spring as things like Weed n Feed are not biodegrable and are literally very poisoness.
I am not an organic gardener but because I have so many roses ( and am lazy) I have noticed that in regards to insects,nature seems to take care of things and if I wait a bug will come along that enjoys eating the bad guys. Black spot is a different matter. A rose gets a trial period of 3 years and if it still gets a lot of disease then it goes on the burn pile. Hope this helps. Lynnette