MARBLEHEAD-Marblehead and Swampscott may be feisty rivals when it comes to high school sports but the two towns can work together on health issues.The Marblehead Board of Health voted unanimously last week to support more state regulation of the chemical Bisphenol A, commonly called BPA. The Swampscott Board of Health took a similar stand two weeks ago.Studies indicate that BPA, used in a sizeable number of food and drink containers, may affect brain growth and other normal development in children 2 years old and younger, according to a report from the Massachusetts Department of Public Health. Connecticut and Vermont have already banned BPA from infant formula and baby food containers, and other states are working on similar bans.The DPH currently proposes a BPA phase-out in baby bottles and sippy-cups but local communities are looking for more. The DPH held hearings on the resolution and the wider ban that Marblehead and Swampscott are supporting last week.The BPA list includes reusable food and beverage containers such as sports bottles and thermoses, infant formula containers and baby food packaging.Massachusetts law allows the commissioner of public health to ban toys or childrens? articles any substance classified as hazardous, so Marblehead and Swampscott are asking Commissioner John Auerbach to expand a proposed BPA regulation to phase out all BPA-containing products aimed at children 3 years old and below.Board of Health member Michelle Gottlieb?s draft position statement was supported by Board Chair Helaine Hazlett and Todd Belf-Becker. Hazlett asked Gottlieb to e-mail documentation on the DPH report to her, but voted in support of the statement.