If you use a picnic table this summer, throwing a tablecloth over it might protect your health.

Chromated copper arsenate (CCA) wood is a chemically treated wood used in many outdoor structures, such as picnic tables and playgrounds. To keep from ingesting harmful chemicals from the wood, throw a tablecloth over the surface and wash your hands before eating.

Mindfully.org note: 
CCA-Treated Wood is known to most people as 'Pressure-Treated Wood' and has a green tint. CCA is a pesticide. And like all pesticides, it kills.

If you know that a picnic table is made of it, by all means, do not sit on it and do not eat food off of it. Do not sit on the ground near it. And do not let children play on it or near it. The rain running off of it is toxic and is found in and on the soil it flows onto. In short, avoid it.

Some studies have revealed that the wood leaches a certain amount of arsenic into the ground.

Researchers speculate that the leached chemicals in the ground also could pose a health threat to children playing near structures made from the wood.