Here is a new quandary that we face, one of many tradeoffs presented by the complexities of 21st century life.

Malignant melanoma ranks as the fastest growing cancer on the planet, its incidence doubling in recent years with nearly all of these cases of skin cancer due to exposure to the sun.

Dermatologists strongly advise applying sunscreen to your body every day if you are in the sunshine, especially during the summer months.

But, and this is a really big BUT, most sunscreens contain ingredients that are hormone disrupters once absorbed by the human body. Known as endocrine disrupters, these chemicals accumulate in the body, as evidenced by their frequent detection in human breast milk, and have been documented as being capable of initiating a range of harmful effects including reproductive disorders and the feminizing of male offspring.

Now an even more disturbing twist has been added to the sunscreen dilemma. Consumer Reports magazine describes in its July issue how tests of 19 common sunscreen products found that eight of them now contain nanoparticles that are NOT identified on the labels. In sunscreens, nanoparticles are used as 'penetration enhancers' to drive chemicals deeper into the skin and ultimately, into our blood and body tissues. Many cosmetics products, particularly skin moisturizers, now contain nanoparticle ingredients.

The risks of nanoparticles to the human body are largely unexplored. Because these particles are so small, 100,000 times smaller than the width of a human hair, it has been assumed they would pose no risk.But the limited laboratory and animal research so far has produced very worrisome findings. Here is a list:

--some chemicals when nanosized become toxic and react much more readily with human tissues.

--nanoparticles enter vital body organs, such as the brain, much easier than previous chemical particles, and application to the skin enables them to bypass the detoxifying enzymes of the liver.

--a class of nanoparticles known as fullerenes have been revealed to damage cells in fish and harm human liver cells and DNA.

--some nanoparticles persist in water supplies and can damage the ecosystem.

Products containing nanoparticles are being developed far faster than toxicologists can test them or even begin to describe all of their potential effects on life.

So what do we do to protect ourselves from skin cancer while avoiding hormone disrupting ingredients and nanoparticles in sunscreens?

First, wear protective clothing or stay out of the sun as much as possible. One popular clothing brand called Solumbra offers swim suits and everyday sun protective clothing with 97 percent ultraviolet protection ( call 800-882-7860 for more information or look up their website.)

Second, use zinc oxide or titanium dioxide sunblocks as an alternative to sunscreens. These products can produce some skin-whitening effects, which may cause consternation for sun worshippers intent on browning their bodies. But look at it this way -- is tanning and vanity more important than your health and your life? It is your choice.