The pretty 22-year old sits across the table in her comfortable home and describes what growing up in south Co Dublin was like: "The number of times I was called a Paki, a nigger, a mongrel, a mixed breed. . ." Her mother's eyes flicker. The daughter continues, with a wry laugh: "Well, I know for a fact that I'm not from Pakistan. And I'm definitely not a nigger."

Her mother looks dazed. "They called you nigger. . ." she says slowly. "You never told me that." Several times over the next few hours, Dr Mary Toomey would repeat those words, disbelievingly: "They called her nigger. . . She never told me that."

To a populace still reeling at the implications of a near-fatal attack on the (white) father of a mixed-race family in Dublin's Pearse Street last weekend, it's hardly startling stuff. Aoife Toomey has no obvious wounds to show for being the child of a mixed-race marriage. No-one has stabbed her, or stood outside her home yelling abuse or urinated through her letterbox.

She is a relaxed, stylish young woman who will shortly have a Trinity politics degree to add to her good fortune as the cherished only child of professional, middle-class parents. In a few weeks, she will marry Matthew, a white, all-American boy, and they will settle in the US.

The wounds only show when she mentions the children she hopes to have: "Everyone thinks I'll come back, but I will not. I'm getting ready to start my life 3,000 miles away in a place where I don't stand out at all. I refuse to feel ashamed of being Eurasian. Here, I am expected to apologise for it, to be thankful and humble and less visible. So I will not bring children up in this place. I'm not whingeing. That's just the way it is."

The wounds run deep. Casual abuse and naked contempt at personal and official levels have marked the long, slow erosion of dignity and identity. Now, the pain and sense of betrayal are manifest in Mary Toomey. A woman of presence and accomplishment, she married Barry Toomey, an Irish engineer, against the will of her parents, high caste Tamils in what is now Sri Lanka. Later, she would ring with good news (another book commission), but to add: "All afternoon, I have heard my mother's voice - `You are forgetting. . . You are selfish. . . My grandchildren will not belong anywhere'. I now see that she was right."

Mary Toomey came to Ireland in 1967 to do a PhD in ecology at Trinity College. "I brought educational assets into this country. The natural sciences were virtually unknown here and biology was being introduced in the schools, so the Department of Education had me teaching teachers from Louth to Kerry."

In a Co Wexford village after Mass on St Patrick's Day in 1968, she was inundated with lunch invitations. "They wanted to touch me and I remember joking: `I'm afraid I cannot part with this tan'. I never once felt uncomfortable."

She was commissioned to write the first biology text books for schools; was headhunted to work at universities; was offered a job by UNESCO (the UN's education and science organisation), to travel across the world, to talk about science education. "I turned it down. I chose to live in Ireland because I loved it. . ."

She is fiercely proud of her Tamil heritage. "We have frescos, culture, carvings, going back to the 5th century BC. In 1963, 90 per cent of the Sri Lankan population were literate and education was prized as the jewel, through every caste. Fourteen per cent of the budget was allocated to education, which was free right through from primary to university."

It's not a boast, just a pointed reminder that a "lily-white" skin is no indicator of learning or accomplishment (and certainly not in Ireland, where a new international survey shows a quarter of all Irish adults are functionally illiterate); that asylum-seekers and even economic migrants ("now made to sound like dirty words"), might have something to contribute, even to smug Ireland; that the next time someone like herself fetches up at Dublin airport, immigration officials there might see more than "a little brown woman" standing before them and dispense with the ritual humiliations.

"Two of the hottest new designers at London Fashion Week are Ugandan-Asians," adds Aoife. "These are the people Enoch Powell made his famous `rivers of blood' speech about, yet the success story of Ugandan-Asians in England is amazing."

The faces of women cleaning the toilets at British and French airports - once invariably Asian or African - are now mainly white again, they remark. "Doesn't that prove something - that where refugees and economic migrants are allowed to work, they will work their hands to the bone and their children do particularly well?"

In her world travels to give lectures and promote her gardening and plant books, Mary is recognised and welcomed at many airports. But not Dublin: "Every time I come back to the airport, it's always the same. No whites in front of me will be stopped. But I will be stopped, and the question, always, will be: `Where are you coming from?' That's before they look at the passport." (The question is relevant to asylum-seekers who, under European law, must be processed in the country of first resort).

Aoife - again with the wry laugh - recalls how after a European trip last year, she and Matthew arrived back at Dublin.

"I got into the EU channel and Matthew, being American, into the non-EU channel. I should have been through well before him. But the guy stopped me, looked at me, and asked how long I had had citizenship. He hadn't even glanced at my passport, which has my place of birth - Dublin - written down. Eventually he muttered something that didn't sound polite and let me go. The irony is that Matthew, a non-EU citizen, had been waved straight through."

Mother and daughter are no "pinko-liberals" in favour of an open-door policy. They are all for proper procedures and controls. Aoife, bound for a new life in the US, sees nothing wrong with the stringent vetting procedures both she and Matthew must undergo. "You should see the paperwork. . . Even Matthew has to supply his tax records for the past four years. Then there's my history - whether I was a spy in 1945, or a member of the Communist party, or a neo-Nazi; or whether I have body-piercing or tattoos. And we'll both be finger-printed and our photographs taken, which must show our right ear and our right side.

"And irrespective of whether he and I stay together, he will be legally responsible for me for seven years. . . But I have no objection whatever. I am asking to be allowed to live in their country after all. The important point about it all is that it's evenhanded; I am treated no differently to anyone else who is going to the US. And it has all been handled with total courtesy, in a way that never compromised my dignity or sense of self."

Mary nods in agreement. "Of course, people must ask questions. But where are the Irish smiles? What has happened to Irish courtesy? Why must they be so stone-faced?"

To Mary, official stone-faces are not new. Roll back 10 years to when she approached a Department of Justice official to seek a study visa for her 17-year-old nephew. "I will never forget that girl who treated me with such contempt. . ." she says, her voice trailing off. "I then made an appointment to see somebody in charge. I lost my dignity, my pride, my arrogance as a high-caste Tamil. . . I pleaded for a two-year visa, I said I would be paying his fees, that he would be going to a private school, that it wasn't in my culture to ask for hand-outs - and to this day, we never have sought handouts, in spite of three redundancies of my husband.

"I got the visa, through tears, beggings, pleadings. I had to do that and yet I am a citizen. I could not bring my mother here, who was found in a refugee camp. There was no procedure to bring a blood relative into this country. Why, as a citizen, can I not do this?"

Compare this with Canadian procedures, where Mary's older sister was able to sponsor another sister and she, in turn, another. And where a brother was able to sponsor her mother.

And now, Mary is "climbing the walls" wondering how her relatives, affluent holders of American, Australian and Canadian passports - one an immigration official in Canada, another a lawyer - will be treated when they arrive in Dublin for Aoife's wedding.

When her nephew, a Canadian passport holder, arrived in Ireland a few years ago to help out in a family crisis, he was "pushed aside, left standing there, until the whole line had been processed, being watched by everyone and treated with contempt. Are they too going to be deprived of their dignity?"

Mary and Aoife can tell stories about racism in south Dublin to equal any in a country village. There's the anonymous woman who has been ringing Mary for three months now (and whose voice she recognises), with the same bleak message: "There's no room for foreigners in this country - you must get out fast."

The "anonymous" girls from Aoife's old convent school who used to ring her with the same racist abuse. The couple sitting opposite her and her friend on the bus, who looked directly at her while spitting bile about a son who couldn't get a job, "yet here's all these coloureds, taking jobs, sponging off the government, and they can hardly speak English".

Into Aoife's lucky bag fell not only a strong father but an enlightened teacher. Niall MacMonagle, an English teacher at Wesley College, Dublin, to which she moved in fifth year, introduced her to thought-provoking writings, such as Maya Angelou's poem, Walking in my Skin. In Wesley, she also absorbed the lessons of Nigerian students whose arrogance "oozed" from them and made her realise that she wouldn't have to spend the rest of her life "apologising for being Irish - and having to explain why I'm not a lily-white Irish girl".

Yet, she's getting out - a decision that saddens her mother beyond words but one which she well understands. Mary will simply never vote again: "The TDs we elected to represent us have not taken care of their citizens. They have let me down."

Letters written to TDs and ministers (the latter about Aoife's treatment at Dublin airport), produced no response. "In the North, they expected Gerry Adams and Martin McGuinness to condemn IRA atrocities, and to use that word," says Mary. "What's so different about this? Where or when has our leader, Bertie Ahern, come out and condemned racist attacks and attitudes, openly, vociferously?"

She believes like many others that the choice of language by politicians is crucial. As Sister Joan Roddy noted this week, the contrasting welcomes given to Kosovar refugees on the one hand and to asylum-seekers on the other, suggest strongly that people take their cue from the Government.

"Ireland has lived in this cocoon," says Mary, "and had this begging bowl mentality. And now we've emerged with an upsidedown begging bowl. Are we educating a whole person through our education system? If so, how can any normal, educated human being take pleasure in humiliating another?

"I had hoped that my child and grandchildren-to-come would have a sense of belonging in Ireland, but that has been removed from my confidence. Therefore I don't want them to come here. Why would I? To see them stopped at the airport and asked `Who are you?'

"My ashes shall be thrown into the sea, for the simple reason that I do not belong anymore. Ireland built me as a person and I am very, very thankful, but now they are robbing me of that. I do not regret a moment of my life here but the question is: do I belong here anymore?"