AUSTIN – Just as Texas is phasing in new high school graduation requirements that call for more math and science, a new study released Monday indicates that a longtime shortage of teachers in those subjects has grown dramatically worse and will continue to do so.

The report from researchers at the University of Texas at Austin also found that the shortage has increasingly meant that less-qualified teachers are used, particularly at schools with lower-income students.

"The students most in need of the most well-qualified teachers were found to be the least likely to have access to such teachers," says the study, funded by Texas Instruments and the Texas Business and Education Coalition.

Among the other key findings:

•The most acute teacher shortages in the state are in secondary math and science. Since 2004, those shortages have increased dramatically, especially in high school science where the shortage has jumped by over 80 percent.

•Projections of future supply and demand suggest that the shortage will continue to increase over the next five years. That shortage comes as Texas high schools implement the 4-by-4 graduation requirements for core courses, including an extra year of math and science. The requirements now apply to freshmen and sophomores.

•Nearly half of prospective math and science teachers in recent years have lacked strong content knowledge in their fields, based on state certification exam results. That is particularly true for those from alternative certification programs, who had lower initial passing rates than graduates of regular teacher preparation programs.

•Secondary math and science teachers continue to earn substantially less than their peers in the private sector, even after adjusting for summers off. Teachers made, on average, between $23,000 and $40,000 less than individuals in nonteaching careers in math and science. The average salary in 2007 for math and science teachers was about $47,000.

•From 2004 through 2008, there were sizable increases in the percentages of math and science teachers who were not certified to teach their subjects. For example, the percentage of high school science teachers who were teaching out of their field jumped from 23 to 34 percent during the period.

Ed Fuller of the Department of Educational Administration at UT-Austin, principal author of the study, called the higher number of out-of-field teachers "an incredibly dramatic increase in such a short time period."

Senate Education Committee Chairwoman Florence Shapiro, R-Plano, said her panel will look for ways to ease the teacher shortage during the current legislative session, including proposed adjustments to the 4-by-4 graduation requirements.

"There would still be math and science requirements, but we would not have as many students taking higher level courses such as calculus and physics," she said.