Environmental themes fit tees

The T-shirt has become a must-have for summer wardrobes.

But not just any old tee.

This summer's hottest top is cozy, made of organic cotton and touts worthy causes across the chest.

From Target to Macy's, retailers at every price point are reserving a place on their sales floors for T-shirts made of environment-friendly materials, emblazoned with friendly phrases like "preserve Mother Earth" or "Do good."

Whether you're a tot or a teen, a male or a female, the eco-friendly tee is the must-have shirt of the moment.

According to a recent MSNBC report, an estimated 2 billion tees were sold worldwide last year. This year's numbers are expected to top that.

The preference of some U.S. consumers for greener products has manufacturers scrambling for eco-friendly fabric options. Choices include hemp, bamboo, tencel, soy fabric, modal and organic cotton.

While wearing a T-shirt is an obvious way to tout your favorite cause, purchasing a shirt made from eco- conscious production methods has a greater impact than you might think.

Most T-shirts are made of conventional cotton, which is one of the most pesticide- laden crops in America. According to the Sustainable Cotton Project, it takes one-third of a pound of toxic chemicals to produce one shirt. That adds up when you think of all those T-shirts sold.

However, when you buy organic cotton, you're buying a product that was farmed using alternatives to pesticides, herbicides and synthetic fertilizers.

You can learn more about organic cotton by visiting the Sustainable Cotton Project at sustainablecotton.org.

There are many ways to shop for Earth-friendly shirts. Here are some interesting and fashion-forward labels from the Web:

Tonic Generation (tonicgen.com): Known for "morally, mentally and physically invigorating" fashion.

Lohas (lohas.com): It's an acronym for Lifestyles of Health and Sustainability.

Patagonia (patagonia.com): A true pioneer in sustainable fabrics; the first to produce organic tees when it wasn't so PC.

Edun (edun-live.com): Edun ("nude" spelled backward) is co-designed by U2's Bono; his wife, Ali Hewson; and fashion designer Rogan Gregory. Edun is founded on four respects: respect for what your clothes are made of; respect for who is making them; respect for where they are made; and respect for the people who are going to put them on.

Tees for Change (teesforchange.com): Specializes in two-word tees made of organic cotton or cotton/bamboo combos.

Fuze (fuzelab.com): Creators of a line of super-soft reversible tees made of organic cotton and eco-friendly ink.

Certaintees (certaintees.com): The site boasts wearable wisdom that is socially positive and environmentally responsible.

Cotam (cotam.org): Short for "Clothing of the American Mind," this site boasts politically aggressive organic T-shirts.