South Portland should not build homes near tank farms | Letter

I write as a concerned citizen and retired family physician.
The South Portland Comprehensive Planning Committee and Planning Board seem set on development, residential and commercial, in the Shipyard district near oil tank fields. Such development means chronic exposure to a number of tank fume toxins.
Monitoring has been done that averages toxin exposure over two-week intervals. This monitoring does not take into account varying wind speed and direction, tank height or bursts of emissions from tank filling. It assumes that a few monitors averaging data will tell all that is needed about the risks presented.
Benzene, one of the toxins being measured, has been identified as carcinogenic at any level. Tanker area monitors have shown levels of benzene above Maine DEP’s own safe level of exposure. This level of exposure is based on a study done with rats nearly 50 years ago that suggests 1 in 100,000 persons exposed would get cancer over 70 years.
Rats have a three-year lifespan while humans average 80. To extrapolate from this rat study to humans is an extraordinary stretch. Most humans are not rats grown under constant laboratory conditions, and free from the multiple toxic chemical mix of tank emissions.
Massachusetts has set its safe level of benzene exposure at one cancer in 1 million people exposed, 10 times lower, safer, than Maine’s standard. I hope South Portland will value the health of its citizens enough to deny residential development near tank farms.