Senior academics involved in teacher training have expressed concern that few physics and chemistry graduates are going into teaching.
They say this makes the education of future generations of much-needed scientists, computer specialists and engineers more problematic.
Dr Peter Childs, a chemistry and education lecturer at the University of Limerick, which provides the State's largest output of science teachers, said the main concern was in colleges which put on one-year HDip courses for graduates. The University of Limerick is unusual in that it runs a four-year course in which students take science and education at the same time.
Dr Childs said he had been unable to get any official figures from the Department of Education, but his own soundings in colleges with HDip courses indicated that for every 20 biology graduates on those courses there were only two or three physics or chemistry graduates.
He said it was vital for more students to get "exposure" to physics and chemistry during junior cycle science classes in second-level schools, to give them a chance to choose the subjects for the Leaving Certificate. With so many science teachers having a background in biology, this was not happening at the moment.
He warned that changing the imbalance between biology graduates and physics and chemistry graduates teaching science in schools would take considerable time, since there were not many new science teacher posts in the system.
Dr Tony Scott, a physics lecturer at UCD who trains science graduates in teaching methods, said few physics or chemistry graduates had passed through UCD's HDip programme in the past decade.
Noting another drop in the numbers taking physics and chemistry in this year's Leaving Cert, he said there was a need for inspirational teachers to make the subjects attractive and dispel the perception that they were hard and difficult to obtain points in.
He noted that an under-supply of physics teachers was an international problem. Since 1991 the number of physics students in German universities had fallen by 50 per cent. In the UK the number of physics graduates training to be teachers fell from 568 in 1993 to 181 last year, and is estimated to be even lower this year.
The American Institute of Physics reported earlier this year that "physics degree production at all colleges and universities across the US continues to decline at all levels".
The Department of Education has pledged £15 million to promote physics and chemistry in schools and is hoping this will result in an increase in the take-up of the subjects in the next few years.