The growing numbers of homicides of infants and suicides among 10- to 14-year-olds are matters of "special concern" in the United States, according to a survey of childhood injury deaths.

Homicide is the leading cause of injury death among children under age 1, and suicide among children aged 10 to 14 increased by 112 percent from 1980 to 1985, a team of Johns Hopkins University researchers report in a study released Tuesday.Though the rate of injury deaths continues a decades-old trend downward, the report said they continue to surpass disease as the major killer of the young.

As a whole, motor vehicle-related accidents, including bicycles and pedestrian-victims, are the major killer of children. The report said 22,174 children died in vehicle accidents during the six years studied. This is about 37 percent of all injury-related child deaths.

Other major causes of death were drowning, house fires, suffocation, unintentional firearms discharge, falls, choking on food or other objects, poison, electrical accidents and farm machinery accidents.

Counting all causes, the average injury death rate among children for the six years was about 19.3 per thousand.

For ages 1 to 4, injuries accounted for 44 percent of all deaths. The rate was 51 percent for ages 5 to 9 and 58 percent for ages 10 to 14.

"The importance of homicide during the first year of life - often representing lethal cases of child abuse - and the increasing rates of juvenile suicide are matters of special concern because they reflect personal, family and social disruption," the study said.

In the District of Columbia, homicide was the leading cause of death among all children up to the age of 14.

In 26 states, injuries suffered as a passenger in a motor vehicle were the leading cause of death for children up to age 14.

For the same age group, house fires were the leading cause of injury death in 11 states; drowning in 10 states; and pedestrian accidents in Massachusetts, New York and Rhode Island.

Motor vehicle occupant deaths were highest in the South and Southwest, but the most lethal state was Idaho, at 7.4 per 100,000 a year. Others were New Mexico, at 6.6, and Wyoming at 6.5 per 100,000 per year.

In contrast, another Western state, Utah, had a motor vehicle occupant death rate among children of only 2.4 per 100,000 per year.

"The low rate of motor vehicle occupant deaths in Utah suggests a beneficial effect on children of social policies (reflecting, in this instance, religious tenets) that reduce alcohol use by adults," the study said.

In an analysis by race, Native American children suffered the most frequent injury deaths, with a rate of about 33.9 per 100,000 per year. Traffic accidents and drowning were the major causes among this group.

Black children were next, with a lethal rate of 29.3 per 100,000 a year. House fires, at a rate of 6 per 100,000, and homicides, at 4.7, were the leading causes.

Injury death rates among white and Oriental children were the same - 17.5 per 100,000 a year. Drowning was the leading single cause among Oriental children, and injuries as motor vehicle occupants was the top killer among white children.