The tests were carried out on farming and non-farming families, but the results were similar for both.
Scientists from University of Galway, who conducted the research, say it shows that glyphosate is present in the general environment, not just around farms where it is most in use.
They hope the findings will help inform discussions taking place in the EU over whether the licence for glyphosate should be renewed when it expires later this year.
Glyphosate is the main ingredient in the most commonly used weedkillers, but controversy has raged over its use for many years because of concerns about its impact on human and animal health.
The World Health Organisation’s cancer research body concluded in 2015 that the chemical was probably carcinogenic.
That finding is not backed by European scientific bodies, but they do accept evidence of other harms to people, marine life, and wildlife.
Thousands of compensation claims related to glyphosate use have been paid out in the US.
The Galway study involved 68 families, 14 of whom lived on farms where glyphosate was sprayed. There were 132 adults and 92 children.
It is essential to understand how chemical exposures can occur among different groups, particularly vulnerable people such as children
Testing found 26pc of the group had glyphosate in their urine. The proportion was slightly higher among children.
The amount of glyphosate found in the urine of farming families was only marginally higher than that found in the urine of non-farming families.
All those tested had glyphosate levels well below what is currently set as the safe limit, but the study was less concerned with the concentrations within individuals than with the extent of the presence of glyphosate in the population generally.
The scientists also tested for AMPA, a chemical left behind when glyphosate exits the system.
They detected it in the urine of 59pc of the test group, although they caution that AMPA can also be left behind by other products.
Dr Alison Connolly, one of the team who conducted the research, said: “This study produced important results on human exposures to a chemical of public concern and is particularly timely with the European Commission currently re-evaluating glyphosate.
“It is essential to understand how chemical exposures can occur among different groups, particularly vulnerable people such as children.”
Team colleague, Dr Marie Coggins, said the findings should inform decisions made concerning glyphosate and its use.
“The data suggests that occupational users may have a slightly higher exposure than background levels, which could and should be reduced further by substitution with less harmful methods, careful chemical handling practices and the use of exposure controls such as personal protective equipment,” she said.
The study is one of a growing number around the world gathering data on the exposure routes and risks of glyphosate.
Research by Trinity College and University College Dublin, released last week, found glyphosate on unsprayed hedgerows where bees gathered nectar and pollen.
Glyphosate weakens and kills bees, while the prospect of glyphosate being present in the honey they make for human consumption also raises concerns.