Is Roof Water safe?

I've been considering a rain barrel. By my house has the regular black sticky/gravely shingles. Is that safe for watering things I want to eat? I noticed that mosquitos take longer to get started in my roof water than they do in regular rain water. Thoughts?

Small amounts of organics will leach off of roof shingles, which may explain what you noticed about the mosquitoes. However, those same organic molecules are very tasty to the soil fungi in your garden. To the fungi, they look a lot like lignin, and the fungi will eat them for lunch.

If you mulch your garden well, then you have a good deal of fungal activity, and anything in your roof water is going to be digested by the fungi and enter the food chain in the way that it should.

Thanks. Organics don't worry me at all - it's the chemicals - arsenic, etc. I can see using it for my lawn or to wash my car, but I'm nervous about veg. They're asphalt shingles that are maybe a couple years old. I have found other thread about the same things, but I can't find any studies that point to fact.

The only real source of arsenic in our modern industrial environment is in the greenish "treated" lumber sold at home stores for outdoor applications. Copper arsenate as a garden spray was phased out in (I believe) the 1940s. To be on the safe side, I wouldn't grow vegetables where the root zone was next to treated lumber, and make sure to keep any pieces of treated lumber out of the hugelbed. They belong in the landfill.