David L. Bazelon, senior circuit judge on the U.S. Court of Appeals for the District of Columbia, cast a dissenting vote yesterday in the debate over the "litigation explosion," calling the dramatic increase in court cases nationally a "healthy" development caused by opening the system to new issues, the poor and minorities.

He said that "for years, the American justice system operated exclusively for those who were wealthy enough to afford it," and he warned the legal profession not to try solving the problem by cutting back on that access.

"Judicial economy must not be purchased at the price of justice," he said in a speech prepared for the University of Washington School of Law in Seattle.

Bazelon, known as a hero to liberals and an arch-activist to conservatives, said recent Supreme Court decisions and Reagan administration cutbacks in funding for legal services threaten gains over the last generation in opening up the judicial system.

Bazelon said the "so-called litigation explosion" is caused in part by the need of a "mechanism" for questioning basic value choices involving science and technology, including development of nuclear power, and problems of occupational health, such as exposure to toxic chemicals.

"American courts must perform a critical oversight function in this arena," he said, "ensuring that the responsibility for making fundamental value-choices is not abdicated to experts who are insulated from political and social accountability."

Another cause, Bazelon said, is creation of new laws and rights helping minorities and the poor bring grievances to federal courts. "For nearly 200 years of this nation's history, few blacks, Hispanics or Asian-Americans, to name only a few of the victims of oppresssion, would have thought of taking their claims to court. They knew they would receive no hearing there."

"If the so-called 'litigation crisis' is due in any significant part to the increase in social expectations of the disadvantaged and to society's growing sensitivity to such issues, and I believe it is, then in my opinion the increase in litigation is a healthy one," Bazelon said.