How is Air Quality Measured?
| Summary: We can all help improve the air quality by taking a few simple steps. Log into the AQMD website to see how safe your air is today. |
Most of us don’t really give the quality of the air we breathe a second thought. Then again, most of us don’t live in Los Angeles. The South Coast Air Quality Management District (AQMD), the air pollution control agency for Orange County and the urban portions of Los Angeles, Riverside, and San Bernardino counties, releases data regarding the quality of the air that 16 million Californians will breathe. Levels of ozone, nitrogen and sulfur dioxides, carbon monoxide, and fine and course particulate matter are measured and analyzed. Although in recent years the Air Quality Index (AQI) of these counties has improved, 68 days in 2003 reported ozone levels twice as high as the federal standard for clean air (40 CFR Part 58). Read more
Allergy Pollen Counts
Depending on where you live, every spring or summer – or perhaps all year round – you leave your house and head to your car to see it covered in a fine layer of yellow powder. Most of us may not think much of this yellow dust (unless, of course, we just washed our cars), but to the 67 million with pollen allergies in the U.S., this is the signifies the onset of months of sneezing, watering and itchy eyes, sinus congestion and headaches, itchy skin, coughing, wheezing, and even stomach aches. So what does one with pollen allergies do?
The pollens that most are allergic to are produced by plain-looking trees, shrubs, grasses, and weeds that usually don’t flower or have rather plain-looking flowers. The male cells that fall from these plants drift to fertilize other plants, but most don’t reach their destination and it’s these that end up being responsible for rhinitis, or hay fever. Since the only way to entirely avoid pollen is to stay indoors, finding out the day’s pollen count is the best place to start. Most television weather reports give the local pollen count as part of the day’s forecast in the first news reports of the morning or online at websites like The Weather Channel’s. But what does it all mean?
First off, pollen levels differ greatly from city to city, which is why it is so important to get your pollen count from a local forecast. It’s also important to take into consideration that even if you can actually see pollen it doesn’t necessarily mean that it’s going to be part of the overall pollen count. For instance, pine trees can produce an enormous amount of pollen, but are not usually part of the pollen count as most people with pollen allergies are not allergic to pine pollen.
It’s also extremely important that you get your pollen count information from a reputable source that has the equipment and resources to give accurate measurements as counts can fluctuate throughout the day. Since pollen concentrations, which are measured by grains per square meter over the course of 24 hours, it’s possible for a pollen count in the morning on temperate, breezy days to be higher than in the afternoon or in humid weather. As some resources only update their information every 48 to 72, you really can’t rely on that forecast when your allergies are at stake.
Pencil
| Summary: Low grade school pencils of the shiny yellow kind come in #1,2,2-1/2,3,and 4, the numbers representing the hardness and weight of the graphite. The lower the number the softer and heavier the graphite. |
Unlike today, where parents have to foot the bill for all of their kids school supplies, when I was in elementary school pencils were shiny and yellow with a black oval number “2” stamped on them below the eraser. Occasionally, a student – one who usually had a difficult time grasping both the concepts of his new writing style and the pencil – would be given a number “3.” None of us, including the offending student, knew why this was. We just knew that it made him “different.” (Usually just one more nail in his casket labeled “different.”)
I never really gave it much thought after that, but then I found myself recently, picking up the random items littering what just might someday become a nice little work corner of my basement, and lo and behold I found a slightly beat-upon, but still shiny pencil. Imagine my surprise when I turned it around and found it was a “2-1/2!” A “2-1/2?” I’d never heard of such a thing. Was this a rarity? Was it like the Holy Grail? And, most importantly, could I sell it on eBay? More investigation was needed.
I began my search online and found out that low grade school pencils of the shiny yellow kind come in #1,2,2-1/2,3,and 4, the numbers representing the hardness and weight of the graphite. The lower the number the softer and heavier the graphite. The softer the graphite the darker the line it leaves behind. So the reason that kids who had difficulties learning their new skills would get harder pencils was that they’d become so deliberate with their writing that they’d press down to hard and make a big old smeary mess on the paper. The harder and lighter graphite kept the writing where it belonged.
But, like everything else in the world, there’s more to it than you think.
First of all, these are low-grade pencils we’re talking about here. When DaVinci was sketching, I guarantee you he didn’t do it with a bright yellow #2. On top of that, we’re about the only country in the world that grades pencils this way and we only do it for cheap pencils topped with little pink erasers that you buy by the dozen. When you start looking at higher quality art pencils, or any pencils anywhere else in the world the grading system is different altogether. Different, and perhaps a little confusing. At least, at first.
High quality pencils used by artists, architects, and the like, have a far wider range of graphite textures and weights to choose from. From what I could find, it would seem that the range of artist quality pencils (excluding the truly random or esoteric) extends from 9B to 10H. How’s that for a curve ball?
But it’s all very simple. “B” stands for “black” and “H” stands for “hard.” So 9B is uses a very soft, heavy graphite – much softer even, than the softest pencils we used in elementary school. 10H describes a graphite that is comprised of a good deal of filler which makes it very hard and light leaving only the faintest line behind.
Now, in between there’s a lot more than just the three or four numbers we had with the school pencils. The range of art pencils are 9B, 8B, 7B, 6B, 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6H, 7H, and 8H.
But wait! You say. You distinctly noticed an “HB.” And what’s this “F” crap? Well you may notice, if you look at enough #2 pencils that they will sometimes have “HB” on them, and , indeed, HB art pencils and #2 school pencils is about as close as you’re going to get in comparing the proverbial apples to oranges. And the “F”? Well, it’s rating of questionable origin. It’s been called “firm,” “fine,” “fine-point,” and I’m sure a few other things, but it’s the best I can do.
Suntan Lotion SPF
| Summary: SPF Suntan Lotion: What do the SPF numbers mean on the suntan lotion bottles? |
Sunscreen Protection Factor (SPF), Sunburn
Remember when you used to go to the beach, slather on a layer of baby oil, and recline with your foil reflector? Now, when you look in the mirror you might see the wreckage, with the fine lines and hyper-pigmentation caused by years and years of basically frying yourself under the sun. Or maybe you’re one of the millions of truly unlucky Americans for whom this behavior resulted in skin cancer (of which one American dies of skin cancer every hour). Whatever the reason, most people have come to realize the importance of sunscreen to preserve their youthful appearance and lower their risk of skin cancer. But there are a few things you should know before you hit the beach – such as the beach may not be the only place you should be using sunscreen.
When purchasing a sunscreen, make sure to look at its Sun Protection Factor, or SPF. The way to determine the right SPF for you is to take the amount of time you usually can stay in the sun and multiply that by 10. For instance, if you can usually stay in the sun for 15 minutes until you start to burn and you buy a sunscreen with an SPF of 20, you can then stay in the sun for five hours. But that’s only if you remember to reapply it after swimming or working up a sweat playing volleyball or going for a run. And even if it says that it’s “waterproof and sweat proof” most doctors will tell you that you still need to put more on as nothing out there, regardless of the claims on the bottle, will really stand up to salt water, chlorine, or a good sweat.
When a lot of people purchase sunscreen, they err on the side of caution and purchase one of the higher SPFs, which can go as high as 60. Others, especially those who still think of a bit of a tan is “attractive” or even “healthy,” will totally underestimate the SPF they really need. But there are ways to take the guess work out of all the numbers. At www.howstuffworks.com one can purchase a reusable credit card sized UV monitor so the proper SPF can be used (it can also be used to actually test the sunscreen for potency and accuracy by smearing some on the card, to test sunglasses, or anything else that emits UV rays)
Earth’s Age: How old is the Earth?
| Summary: The age of Earth has been estimated by analyzing how long it takes for the radioactive elements of uranium to decay into lead. How old is the sun and how long will it last? |
Well, the universe itself is thought to have had its beginnings with the Big Bang which occurred anywhere from six to fifteen billion years ago. The Big Bang was a gigantic explosion which catapulted enormous amounts of matter rocketing through space. Eventually the matter was pulled by gravity into the beginnings of present day galaxies and solar systems. Many believe the formation of the earth began at least 4.5 billion years ago, that’s 4,500 million years. This age has been estimated by analyzing how long it takes for the radioactive elements of uranium to decay into lead. The fossil record also backs up this estimate of our planet’s age.
And just how much is a million? Well, if you start counting now and count one number every second for eight hours a day seven days a week in just over a month you may have counted to a million.
Earth rocks as old as 3.6 to 3.9 billion years old have been discovered around Greenland and the Northwest Territories of Canada. The first animal life on earth is relatively new. It occurred only at the end of the Precambrian Period a little over 500 million years ago.
And how old is the sun?
The sun is also believed to be about four and a half billion years old which means it is about middle-aged as most scientists believe it will burn out in another 5 billion years. How does a star that is about 900,000 miles across (that’s more than 100 times the width of the earth) burn out?
Wait, wait, you say the sun is a star?
That’s right, the sun is a star just like the little twinkly ones we wish on at night. It’s just a lot closer to earth, so close in fact that we can feel the warmth of its enormous heat. At its center the sun has a temperature of more than 10 million degrees. The sun’s surface, the part we see, is about 5,800 degrees but the outer reaches of its atmosphere heat back up toward two million degrees. And, oh yes, in another 5 billion years or so it is expected that the sun will begin to expand by about 100 times turning it into what is scientifically knows as a red giant. At that time the sun will have burned up all of its helium and will collapse in on itself and become just a white dwarf.
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