Source: University of Auckland, 22 December 2016
Gas heaters used for home heating have been found to increase
the risk of respiratory illnesses in young children, according to
the latest research from the University of Auckland.
Paediatrician Dr Cameron Grant from the University's Centre for
Longitudinal Research, says the results of the research project
point to a worrying finding that the risk of hospitalisations for
acute respiratory infections in under-five year olds was increased
in households where gas heaters were used to heat the room the
child slept in during their first year of life.
"The quality of housing, particularly for young children, is an
issue of major concern in contemporary New Zealand and has most
recently focused on known problem areas of cold, dampness and
cigarette smoke," he says.
Acute respiratory infections are common in early childhood,
accounting for many doctor visits and hospital admissions.
Specific aspects of children's home environments have been shown
to increase the risk of these infections before age five. These
include the presence of dampness and mould, household crowding and
exposure to air pollutants produced by heating, cooking and
The relationship between internal living environments and
respiratory disease was investigated by a research team from the
Centre for Longitudinal Research as part of the longitudinal study
of child development, Growing Up in New Zealand.
The study was published recently in the
journal, Environmental Health.
"In this study one in five mothers reported frequent presence of
dampness and condensation in the room where the child slept," says
Professor Grant. "Although these factors were positively linked to
the incidence of acute respiratory infections, the association was
no longer statistically significant after we adjusted for the use
of gas heating."
"The independent relationship with gas heating identifies this
as an area which, if addressed, could reduce the number of children
admitted to hospital with these respiratory infections," he
The most common forms of heating are solid fuel burners and
portable electric heaters. Among the 7000 Growing Up in New
Zealand participant families, one in seven mothers reported
using a flued gas heater, and one in eight an unflued gas heater,
for household heating.
"Unlike electric and solid-fuel burning heaters, gas heaters
(particularly if unflued) emit moisture and a number of pollutants
including nitrogen dioxide, carbon monoxide, carbon dioxide and
formaldehyde, which affect children's respiratory health," says Dr
"This is a type of household heating that has been banned in a
number of other countries, but there are no such restrictions in
"The burden of hospital admissions for acute respiratory
infections among children in this nationally representative study
is considerable," he says. "Our study demonstrates a significant
association between the risk of acute respiratory infection
hospitalisation before five years of age and the use of gas heaters
in the child's room during infancy.
"Reducing our reliance on gas heaters in New Zealand households,
alongside other measures to improve housing conditions, would be a
major step forward in improving our children's indoor living
environments and thereby health," says Dr Grant.
Study Results in brief
· Study participants comprised 6112 children from
the Growing Up in New Zealand longitudinal child cohort
study whose mothers provided information about the household living
environment in a computer assisted face to face interview when the
children were nine months old.
· Forty eight percent of mothers reported living in rental
accommodation; 22 percent reported household crowding and 20
percent dampness. Twenty percent reported heavy condensation and 13
percent mould or mildew in the room where the child slept.
· Fourteen percent of mothers smoked cigarettes while 30 percent
of households contained other family members who smoked.
· Eleven percent of homes did not use any form of heating. Of
those that did 89 percent reported using electric heaters, 14
percent flued gas heating, 12 percent unflued portable gas heating
and 30 percent used solid fuel burners (wood and coal). Three
percent of homes used flued gas heating and one percent used
unflued gas heaters in the child's room.
· Hospital admissions were determined through linkage to the
Ministry of Health database of hospital events covering the period
from birth to five years of age. 708 children (twelve percent) were
hospitalised with a diagnosis of ARI during their first five years.
553 (nine percent) were hospitalised once only while 18 were
admitted five or more times.
· The incidence of ARIs requiring hospital admission was 33
children per 1,000 per year. This is a higher rate than those
reported in a recent global assessment and may in part be explained
by the relatively poor condition of the home environment, where New
Zealand currently ranks 20th and 17th(respectively) for children
living in crowded and poor households.