Oakland is hella polluted.
It's not good for kids, especially kids with asthma. Read more on the air pollution entry.
Scientists still aren't sure the best way to fix it. In 2012 the EPA did an experimental program to absorb the lead using ground up fish bones. See these articles by the Coast Guard, EPA and NIH. They have a Facebook page. You can buy your own fish bones at $10/lb but nothing you grow will ever be vegetarian.
There's a Wikipedia article about this.