Boston — It was a poignant letter from a schoolteacher in India. She had written Philip Jackson to say that she was solely responsible for her mother, aged 70, her father, 74, and an aunt, 68, all of whom were in failing health. On her salary of 150 rupees a month (about $15), she made barely enough for them all to live on. And whenever she had to stay home to care for her family, she risked losing her job. Could someone help?
''I contacted some of our field workers in India and asked if a group of volunteers could organize themselves to be available to this woman when she had a problem,'' Mr. Jackson recalls. ''What she needed was someone who would go to her house during the day so she could go to her job and have a little bit of self-respect and dignity by having a small income and not being dependent on charity.''
In this instance, Mr. Jackson was able to provide immediate help. ''But you have to remember that's only one of tens of thousands of similar situations in India and throughout the developing world,'' he adds.
As director for Asia of Help the Aged (HTA), the largest international charity exclusively concerned with the welfare of the elderly, Mr. Jackson is regarded as a leading world authority on the subject of aging. He generally spends half of each year visiting HTA programs in Asia, and the other six months at home in Britain, raising funds for those programs. Working closely with local organizations, Help the Aged volunteers have built homes for the elderly, provided food, water, and clothing, and often donated weaving looms and laundry facilities to encourage useful activity.
During the past few months, Mr. Jackson has also been involved in plans for this summer's United Nations World Assembly on Aging, to be held in Vienna July 26 to Aug. 6.
For the first time in its history of convening special sessions, the United Nations encouraged nongovernmental agencies to meet together before the official conference to make recommendations for the assembly agenda. As a result, some 300 representatives gathered in Vienna during the last week of April to discuss what they considered to be the most pressing concerns for the world's aging.
''Most of the countries in the third world haven't realized yet that there is a problem, that they've got growing numbers of old people being cared for less and less by traditional methods,'' Mr. Jackson explains. ''What the world assembly is really meant to do is to focus attention on the facts of aging, and the consequences of those facts.''
The facts Mr. Jackson refers to are startling:
* The number of people aged 60 and over is the fastest-growing population in the world. Although there were only an estimated 214 million older people in 1950, by 2025 that number is expected to reach 1.121 billion.
* In the developing world, the number of people over 60 is expected to increase nearly seven times between 1950 and 2025, to a point where 72 percent of the so-called ''over-60s'' will be living in third-world countries in 2025.
* People are growing old faster than children are being born to support them in their old age. In 1950, for example, for every 100 adults aged 15 to 59 there were only 19 persons over age 60, compared with 45 children under the age of 15. By 2025, however, there are expected to be 40 persons over 60 and only 35 children for every 100 adults.
In his travels throughout Asia, Mr. Jackson says he sees constant evidence of the kinds of changing social patterns that could add yet another dimension to these figures. ''In Korea, for example, traditional Confucian patterns, whereby elderly parents always lived with, and were cared for by, their sons or daughters, are beginning to erode,'' he notes. ''It's a consequence of industrialization and of the mobility of the young seeking jobs that these traditional family units are splitting up. And it's not unique to Korea.''
Today's developing nations are apparently following the same patterns of caring for older people that have been established in the developed West. At first, people tend to look to institutional care as the answer, and then, after many years, they begin to consider noninstitutional, or at-home, care. ''What's interesting is that many Asians who have been to America have seen the way old people are almost totally ignored here - how they may have all the modern facilities available, but still are left with nothing, leading totally spiritual-less lives,'' Mr. Jackson continues. ''They see this in America and other countries, but they're blind to the fact that they themselves are proceeding along exactly the same lines.''
He points out that India will have a population of about 70 million people over 60 by the end of this century. Even if it were desirable, Mr. Jackson says, that number of people could never be cared for in institutions. ''For one thing, there's no way it could be physically done. And even if it could be done, caring for people in a hospital, a nursing home, or some sort of institution is infinitely more expensive than caring for them in their own home.''
For these reasons, Mr. Jackson and the volunteers of Help the Aged are doing all they can to advocate the responsibilities of both the family and the community in caring for older people. Although traditionally there haven't been resources or organizations in countries like Korea and India to provide support to people looking after elderly relatives, these now are beginning to appear.
''In the past, the aged haven't been able to expect much attention from their families because their families have been too busy trying to survive,'' Mr. Jackson explains. ''But we're now engaging some social workers in places like Bombay who go to visit people, who take them outside their homes and train them in self-respect. It's all very basic, elementary stuff, but it's the kind of thing that's needed.''
Hastening to add that many geriatric theories now are being challenged in the countries he's visited, Mr. Jackson says that a number of programs have been set up to train older people to revive traditional crafts or adopt youngsters as foster grandchildren. ''It used to be that if someone was old, you did what you could for them and kept them comfy in bed. Now, you literally bully them out of bed, get them moving, on their feet, doing something.''
These are the kinds of attitudes and issues Mr. Jackson hopes to bring to the attention of the UN World Assembly on Aging next month. ''Tomorrow's older population is already born,'' he notes, ''and what we're really doing is educating ourselves about the problems and the values that old people bring to society.''