Hi, Julie,
There is a Vieques Peeps page on Facebook where you might find some good advice.Â
I've been to the island a number of times and heard people talking about their toxic waste dump, which begs the question, "then why are you here?" If it were that bad, they'd all leave. Part of the island is closed off and uninhabited due to unexploded ordnance.Â
I have a friend who lives there and has a garden. She has a mango tree and a lime. She eats the fruit and has never had any qualms about it.
Definitely check out that page. I think you will find some good help there.