A study concludes that Seattle's weaker gun control laws probably explain why the risk of being killed with a handgun there is five times higher than in nearby Vancouver, British Columbia.

The researchers said that Seattle has a higher overall homicide rate than Vancouver, and virtually all of the difference can be explained by the city's higher incidence of handgun shootings.The researchers cautioned that similar studies should be done in other cities, but they said their work suggests that "a more restrictive approach to handgun control may decrease national homicide rates."

The study, directed by Dr. John Henry Sloan of Harborview Medical Center in Seattle, is being published in Thursday's New England Journal of Medicine.

The researchers noted that Vancouver and Seattle are similar large cities 140 miles apart in the Pacific Northwest. However, the Canadian city has tougher gun laws.

In Vancouver, self-defense is not a legal reason to buy a handgun, and concealed weapons are not allowed. Permits are required to buy and transport handguns, and those obtained for rec-reation can be fired only at licensed shooting clubs.

Opponents of gun control argue that limiting access to guns will have little effect on homicide rates, because those who want to kill will find ways to obtain guns or will use other weapons.

However, the researchers said Vancouver's rate of homicides with other kinds of weapons was not significantly higher than Seattle's, "suggesting that few would-be assailants switched to homicide by other methods."

Other findings of the seven-year study included:

- The risk of being a homicide victim in Seattle was 63 percent higher than in Vancouver. Virtually all the increased risk in Seattle was due to a five-fold higher risk of homicide by firearms, almost all of them handguns.

- The rates of burglary, robbery and assaultwere similar in the two cities.

- Indians had the highest homicide rates in both cities.

- Asians in Seattle had higher homicide rates than their counterparts in Vancouver, but there was little differences in other racial groups between the two cities.

In an accompanying editorial, Drs. James A. Mercy and Vernon N. Houk of the U.S. Centers for Disease Control in Atlanta said the research is a step toward studying gun control scientifically. They said more such work should be done.