Ed Masood drove home wearily in a heavy downpour, blackness obscuring the rural road east from Poolesville. It was after 10 p.m. on the 14th working day of October, and Masood, head of the Montgomery County public school system's department of driver, health and physical education and athletics, had just finished lecturing at his 14th AIDS informational meeting for the month.

The former high school athletics coach, a powerfully built man of 45 who uses his annual leave to referee student wrestling competitions, is rarely at his home in Montgomery Village these weekday evenings. He has taken to the road to speak out against a disease that he calls "the most horrible thing I've ever seen in my life." Since 1981, AIDS has killed 76 Montgomery County residents.

Masood, the father of two college students, tells other parents that he worries increasingly about the temptations life throws in the path of young people in an age of AIDS. He worries that teens may drink too much, for instance, and their inhibitions would fade, leading them to sexual encounters from which they could develop AIDS.Acquired immune deficiency syndrome is a disease that can be transmitted sexually and through the sharing of hypodermic and other needles, and it most often affects people in their twenties and thirties. Once predominantly an affliction of homosexual men in this country, it is increasingly striking women.

"It is inappropriate not to worry if you're not homosexual," he told the Poolesville audience.

"I don't care where the disease originated, I don't care how it got to this county," said Masood, who watched a friend, Redskins all-pro Jerry Smith, die of AIDS. "My concern is how to stop it." That has kept Masood on the lecture circuit for more than 1 1/2 years, ever since the county school system launched an effort to educate its students about AIDS prevention. County health officials began such efforts in the community even earlier, about three years ago, and have established a dozen-member speakers bureau on AIDS.

At the request of principals, parent-teacher association presidents and other civic leaders, Masood speaks from one end of Montgomery to the other, before school staff, parents and students. Fall and spring are his busiest times, he said.

A concerted public information effort drew more than 200 students and parents at one recent AIDS informational meeting at Sherwood High School in Sandy Spring this month. But turnout at such gatherings typically is low, Masood said. "That's why we have to go back time and time again," he added.

"A lot of people don't want to go to seminars about AIDS because they think they know enough or are not among one of the high-risk groups," he said. "They think it's not their problem, so they say to themselves, 'Why waste a night to go out and learn something I already know about?' That's a totally wrong approach for people to take."

Close to 30 parents and a few students attended the program Masood and health professionals gave at Poolesville Junior-Senior High School on Oct. 20. But Masood said he would haul out his notes and his informational film if only one person were in attendance.

Since 1981, 121 cases of AIDS have been reported in Montgomery, and the death toll in the county is the third highest in Maryland, behind Baltimore (175) and Prince George's County (188). By the year 2000, Montgomery's cases may reach 3,500, estimates Dr. James Bond, the county's AIDS coordinator.

So far, no county student is known to have been infected with the AIDS virus, school officials said. State education officials will vote next month on plans to begin mandatory AIDS education as early as elementary school. It is already included in secondary school courses in Montgomery and Prince George's counties.

Masood's talk in the Poolesville school was his seventh in the small western Montgomery community this year, and as far as he is concerned, "it's still not enough." He drove there last month to help allay concern at Poolesville Baptist Church and at Poolesville Elementary School about student and staff contact with the children of an AIDS patient, a church member who is the first person known to have the disease in the town of 3,400.

The woman's two children, as well as other members of her family, are being tested regularly and show no signs of infection, Masood told parents and school staff members. AIDS cannot be transmitted through casual contact, he emphasized.

County health workers, including Bond, also have traveled to Poolesville to answer questions raised by members of the church in recent months.

Pat Pierce, who went to the high school to hear Masood, had missed an earlier meeting at the elementary school, where she is a member of the PTA. She said that "rumors were flying" about the children of the AIDS patient and that she was concerned about a lack of information about the youngsters, who continue to attend the school.

But PTA President Tookie Gentilcore said 600 fliers had been sent home with students about informational meetings, and a few parents had attended them. Since then, questions about the children "have blown over," she said. "Everybody in the community is very calm about it now. We do not have a child with AIDS in the school, and that's the bottom line."

What happens when the first Montgomery student with AIDS is reported will be governed by policies that Masood helped develop and the county school board adopted. They did not call for the automatic barring of AIDS patients from county classrooms, but instead established a medical advisory committee to review cases and make recommendations to the school superintendent about staff members or students infected with the virus.

Two county teachers are known to have died from the disease since 1985, but both were too ill to return to teaching by the time they were diagnosed, school officials said.

The school system is hearing little opposition to the teaching of AIDS prevention in the classroom, Masood said. There was a flood of mail in 1980 when he was working on curriculum changes for instruction about sexually transmitted diseases, he said, but virtually none over AIDS instruction. At Poolesville Junior-Senior High last week, Masood answered questions about risks -- he urged parents to forbid their children to share tattooing or ear-piercing needles, for instance -- and talked about the controversy that had briefly arisen over the children of the local AIDS patient.

"Testing is being done every three months in that family," he told the gathering in the school's choral room. "I bet they will continue to show up to be negative. Normal household contact is not a way to transmit this disease . . . . Normal classroom contact is no threat."

But, he said, alluding to an attempt at the Baptist church to bar the family from attending services, "It's kind of a shame, the way some people are dealing with the kids. It's kind of tragic. If you're going to hate anything, hate the virus and not the patient."