The gold standard for certifying "green" buildings fails to place enough emphasis on human health and needs to be upgraded, according to a new report from an environmental health group.

The standard - Leadership in Energy and Environmental Design, or LEED - is weighted more heavily toward energy conservation and not enough toward health protection, skewing green-design criteria, concluded Environmental and Human Health, Inc., a Connecticut-based nonprofit dedicated to protecting human health from environmental harms.

"They have to be given great credit for work on energy conservation. And there clearly are environmental quality and health benefits that will accrue from conservation efforts," said John Wargo, professor of risk analysis and environmental policy at Yale University and a lead author of the report, released in May.

"But (LEED) has got some serious problems with respect to environmental quality and human health."

The LEED system provides third-party verification that a building or community is built according to several metrics aimed at promoting sustainability: Energy savings, water efficiency, CO2 emissions reduction, improved indoor environmental quality, stewardship of resources and sensitivity to their impacts.

Municipalities and states increasingly are incorporating LEED criteria into their local building codes; the standard is gaining traction oversees.

The nonprofit U.S. Green Building Council, which administers LEED, acknowledged gaps in the standard and welcomed both collaboration and improvement. But it warned that the health report missed or understated fundamental aspects of the program's efforts to improve human health and the environment.

In their report, the Environment and Human Health scientists point   to several blind spots in what is often seen as the "gold standard" for sustainable design.

For starters, increasing evidence suggests several compounds commonly found in homes and building products harm human health and the environment, including bisphenol-A, polyvinyl chloride, plastic additives know as phthalates and many of the chemicals found in rubber infill used in artificial turf. LEED neither restricts the use of these chemicals in building materials nor awards credits for projects that avoid these projects, the report's authors noted.

And while LEED encourages reduced water use and conservation of energy necessary to acquire, distribute and sanitize it, the protocol offers no credit for drinking water quality and establishes no goals for testing or filtration.

Yet criticism that LEED fails to protect human health misses the mark, countered Brendan Owens, vice president of LEED technical development for the Green Building Council. The Environmental and Human Health report, he said, discounts health benefits that accrue from reductions in energy and water use or from LEED's emphasis on integrative design, where builders must consider a number of disparate elements in concert rather than independently.

"When you reduce the amount of electricity being pulled off the grid, you're reducing the amount of coal being burned and reducing the amount of mercury being burned," he said. "There's a direct result to human health."

Some designers caution that LEED is simply a tool. It has, they note, pushed the building industry in important directions and raises the bar for designers and builders.

"As in any tool, it can be used poorly and for the wrong reasons, or correctly and for the right reasons," said Gunnar Hubbard, principal at Fore Solutions in Portland, Maine, one of the nation's leading green-design consulting firms. "As we learn, LEED is intended to work with that knowledge."

But others on the green building frontier say LEED is part of a larger and more intractable problem: The American lifestyle as a whole is unsustainable. Building large green houses in the suburbs - even if the homes themselves are energy-sipping, chemical-free and LEED-certified - is by no means environmentally benign.

"LEED is not going to save us. It's good. It's better if that guy who's walking to work, instead of living in an inefficient old house, lives in a small and efficient house," said Florian Maurer of Allen+Maurer Architects in British Columbia.

"But LEED-platinum houses in virgin subdivisions? That is the one thing that needs to be eliminated. No matter what standard, a 4,000-square-foot-plus home for a retired couple ... is unacceptable."

The report recommends several steps:

* Instead of a single "silver," "gold" or "platinum" certification, rank building performance within various categories - health, energy, site, neighborhoods, among others - on a 0 to 100 scale, correcting what the report calls a "common misimpression that certified LEED buildings perform well in all categories."

* Diversify LEED certification categories into health and other areas.

* Broaden the Green Building Council's board to include health and environmental science experts. Today just one director among 25 has formal medical or toxicological training - an imbalance, the report asserts, reflected in LEED's present priorities of energy conservation, site planning, and design.

* Encourage more federal testing of chemicals used in building products.

The authors conclude that the task of certifying green design and defining "sustainability" for the nation's houses, offices and communities is simply too large for one nonprofit.

Uncle Sam must step in, said Nancy Alderman, the group's president.

"The Green Building Council is setting the green building standards with no oversight," she said. "That's problematic."

Alderman called for a two-step solution: Improve LEED and let the Green Building Council continue to push standards higher, and get the federal government to   oversee green standards.

But federalizing green standards creates other problems, cautioned Hubbard, the green building consultant. LEED's appeal - and growing popularity - as an international design standard comes in no small part because it is not tied to any government, he said.

"That's not to say government can't help raise the bar and ensure more buildings succeed," he said. "But I think it's that balance of public/private/(non-governmental organizations) that can help make (green design) thrive."

Owens, of the Green Building Council, said the council and the health experts "generally see eye-to-eye" on many of the points raised in the health group's report. LEED is being continuously upgraded, he said. The council is open to improvements on toxics, health and climate change standards.

Just don't expect a fundamental revision of the ratings system.

"They're asking us to modify one of the things that have made us successful," Owens said. Its simplicity has allowed LEED to lift sustainability to the forefront of the building industry.

"We can demonstrate that to anybody who wants to slog through what amounts to 10,000 data points. But asking an architect to do that on a 15,000 square-foot office building is pushing a rock uphill," Owens said.

This article originally ran at The Daily Climate, the climate change news source published by Environmental Health Sciences, a nonprofit media company.