Calif. heat wave deaths undercounted, data show

San Jose Mercury, via AP: The heat wave that scorched California a year ago may have contributed to the deaths of three times as many people as the state has officially reported, an Associated Press investigation suggests.

As recently as last month, state officials reported that the two-week period of triple-digit temperatures that began July 14, 2006, killed 143 people. Statistics compiled by the AP from each of California's 58 counties show the number of deaths last July was 466 higher than the average over the previous six years, a spike many health officials attribute to the record heat.

In Sacramento County alone, the July 2006 death toll was more than 100 over the average.

"I cannot account for any event that could have caused that, other than the heat wave," county Health Officer Glennah Trochet said in response to the AP's research.

The discrepancy is important because it suggests an inadequate statewide reporting process and indicates that state and local agencies must do more to monitor and care for those who are most vulnerable.

…The length and severity of last summer's heat wave provided a sense of urgency: the number of deaths reported by the state roughly equaled those killed in the Northridge and Loma Prieta earthquakes and the 2003 Southern California wildfires combined. While heat waves don't cause the billions in damage that an earthquake might, they could become California's most tragic recurring natural disasters.

…Experts who reviewed the data said that even after accounting for California's population growth, the statistics show the official toll provided by the California Office of Emergency Services significantly underestimated the deaths attributable to the heat.

"Those are gross under-exaggerations of what is really happening," said Laurence Kalkstein, who heads a climatology laboratory at the University of Miami and tracks heat wave deaths. "I would be quite confident that 143 is well below the actual number of heat-related deaths. In general, we see underestimates (of such deaths) by a factor of two or three."

Deaths from heart attacks, strokes and respiratory illnesses can double during extreme temperatures, while deaths from all causes increase, said Kalkstein, president of the International Society of Biometeorology….