Washington ? From algae blooms in the Chesapeake Bay to heat waves, drought and fires consuming the West, global warming is stirring up public health problems that are likely to worsen, witnesses told a Senate committee Tuesday.

They pointed to as many as 35,000 deaths in 2003 during a summer heat wave in Europe. They cited the spread of the West Nile virus, unseen in the United States eight years ago, to 47 states.

It’s not a question of if there will be health effects from global warming, said Julie Gerberding, the director of the Centers for Disease Control and Prevention. “It’s a question of who, where, when and how,” she said.

The testimony came during the 19th hearing this year on global warming held by the Senate Environment and Public Works Committee. Next week the committee’s global warming panel begins work on legislation introduced by Sens. Joseph Lieberman, I-Conn., and John Warner, R-Va., to cut emissions by 60 percent by 2050.

The legislation would allow states such as California to move ahead with even tougher laws. California has been fighting the Bush administration over its groundbreaking law and is expected to file a lawsuit this week against the Environmental Protection Agency for delays in issuing a waiver it needs to impose limits on car and truck emissions.

The White House severely edited congressional testimony given Tuesday on the impact of climate change on health, removing specific scientific references to potential health risks, according to two sources familiar with the documents.

Gerberding’s prepared testimony was devoted almost entirely to the CDC’s preparation, with few details on what effects climate change could have on the spread of disease. Only during questioning did she describe some specific diseases that likely would be affected, again without elaboration.

Her testimony had much less information on health risks than a much longer draft version Gerberding submitted to the White House Office of Management and Budget for review in advance of her appearance.

“It was eviscerated,” said a CDC official, familiar with both versions, who spoke on condition of anonymity because of the sensitive nature of the review process.

The official said that while it is customary for testimony to be changed in a White House review, these changes were particularly “heavy-handed,” with the document cut from its original 14 pages to four. It was six pages as presented to the Senate committee.

OMB spokesman Sean Kevelighan said reviews take into consideration “whether they … line up well with the national priorities of the administration.”

Sen. Barbara Boxer, D-Calif., the committee chairman, in a statement Tuesday night said the Bush administration “should immediately release Dr. Gerberding’s full, uncut statement because the public has a right to know all the facts about the serious threats posed by global warming.”

The Bush administration has been trying to defend itself for months from accusations that it has put political pressure on scientists to emphasize the uncertainties of global warming. Earlier this year a House committee heard testimony from climate scientists who complained the Bush administration had sought frequently to manage or influence their statements and public appearances.

The White House in the past has said it has only sought to provide a balanced view of the climate issue. The CDC is part of the Health and Human Services Department and its congressional testimony, as is normal with all agencies, is routinely reviewed by OMB.

Deletions included details on how many people might be adversely affected because of increased warming and the scientific basis for some of the CDC’s analysis on what kinds of diseases might be spread in a warmer climate and rising sea levels, according to one official who has seen the original version.