A lack of affordable housing threatens to worsen the Washington area's already troublesome labor shortage, according to a report released yesterday.

Some area industries -- real estate, retail and defense contracting -- are experiencing somewhat of a slowdown at the moment.

But the Greater Washington Research Center report said the housing problem could be an even greater long-term threat to the area's economic health.

If the supply of lower- and middle-income housing does not increase enough, people will be unwilling to move to the area, especially to take less well-paying jobs, the report's author said.

"We are at a crisis point in terms of our ability to keep our economic growth going," said George Grier. "We can't keep it going on scientists, engineers, CEOs, doctors and lawyers. We also need secretaries, receptionists, repair people, delivery people."

Because the number of jobs in the area has increased faster than the population over the last 20 years, the area badly needs new workers.

More than three-quarters of those who have moved to the area in recent years did so for a job, the report found. And 80 percent of the newcomers rented when they first arrived. (The figures are for 1985, but Grier said that, if anything, the situation has worsened since then.)

But the new workers, especially those with modest incomes, found that rent absorbs a large portion of their salaries: Nearly 30 percent of recently arrived renters with incomes of less than $30,000 spent more than 50 percent of their gross income on housing, and 45 percent spent more than 40 percent.

The problem is not the total housing supply, which has grown faster than the population, the report said.

Most of that growth has been in single-family houses, while lower-income individuals and families most need apartments or other types of low-cost housing.

Despite the weakness of some industries in the area, Grier and others said the underlying economy is sound.

"The industries that are not affected {by the slowdown} -- associations, international, biotech, law, professional services -- find that the type of people and skills they need are still in short supply," said William B. Wrench, president of the Greater Washington Board of Trade.