The council said the presence of dioxins was yet to be confirmed with local tests, which would require specialist equipment to arrive from overseas.
Dump owner John Campbell refused to talk about the alert to RNZ; last week he ridiculed locals' health fears as made up and bordering on "hysteria".
Jeanne Ree of Pukemiro got the notice at the weekend.
Her daughter-in-law from Hamilton had visited three weeks ago.
"She came to announce that they were having a baby. The next day she was sick.
"I don't know... I'm hoping it's got nothing to do with that. After receiving that letter on Saturday, it's made me question whether it was that."
The notice was the end of having her daughter-in-law or other family to visit, Ree said.
"She can't come here, no way.
"Because of the contaminants, because we never know what we're going to smell.
"It's shocking. It's absolutely shocking."
Her grandchildren from out of town would have to stay away.
"I don't want any of them here. I don't even want my grown daughter here or my other grown son without their children."
Her other two grandchildren, aged 10 and "going on 12", who went to Glen Massey School halfway to Ngāruawāhia, woke up some days and asked their mother "is it smelly today?".
Their family would be staying put.
"Because they've got commitments, they've got animals, they've got school, jobs... I don't know anybody that could just up and leave their home."
Campbell said on Friday he had seen no sign of the fire for four days.
However, yesterday three local people told RNZ they had woken once more to the smell of burning.
The dump is for construction and demolition waste. It was granted a wider consent several years ago to take municipal waste, but the regional council said it never did so as it did not meet the consent conditions.
The regional council is investigating if the dump has breached its resource consents.
Campbell has accused the council of bias towards "local activists".
Ree bristled at that.
"I'm definitely not an activist.
"I'd definitely rather be sitting at home or be in my garden, then out, going to meetings ... or being on Facebook, seeing what people's fears are."
Locals have called a meeting for tonight, the second in a few days about the fire.
It was not right that Campbell could subject 400 people to such a longstanding nuisance, Ree said.
"It's basically taken over my life, to be honest."
