The environment in which we live influences our health.
However, the link between environmental quality and health effects is a complex
one. Not only the environment, but also factors such as lifestyle and genetic
predisposition determine the health of individuals. Commissioned by MIRA, VITO
developed for Flanders a first set of environmental health indicators for six
pollutants. The study shows that many of these pollutants in our body have been
decreasing over the last decade, but that the risk of health effects cannot be
Environmental indicators based on results
of human biomonitoring
measurements in humans ...
Human biomonitoring (HBM) is a method that measures internal
exposure to pollutants directly inside the human body (e.g. in blood, urine,
hair, etc.). The pollutants may originate from various sources and enter the
body through different routes (including contaminated air or food). Over the
last few years (2002-2015), three HBM campaigns were conducted in Flanders as
part of the activities of the Flemish Center of Expertise on Environment and
Health: FLEHS or Flemish Environment and
Health Study I-III.
to a first set of environmental indicators for Flanders
In this study report, an attempt was made to use information
on exposure to pollutants (the Flemish HBM results) for the assessment of
health risks. To this end, the biomonitoring data were compared with health based
benchmarks (HBBs). Based on literature research, quality criteria and expert
surveys, six pollutants were selected from the available Flemish biomonitoring
data and converted into indicators.
What are the results?
Concentration in the human
body of 4 of the 6 selected pollutants is decreasing
Both for the selected heavy metals (lead, cadmium and
arsenic) and for the persistent organic substances (PCBs, HCBs and PFOA) the
concentration in the human body decreased in two out of three cases. Average
lead and cadmium concentrations have declined over the last decade (see figure
for cadmium). Lead values in newborns have even halved. Concentrations of
persistent organic substances in the human body, such as PCBs in adolescents and
HCBs in adults, have also decreased over the last decade. For arsenic and
perfluorooctanoic acid, by contrast, no clear decrease has been observed (yet).
Health effects cannot be excluded
Despite a decrease in exposure for four of the selected
pollutants, health effects cannot be excluded for any of these substances. For
the majority of the examined participants, for example, a possible risk of
effects on intelligence (as a result of lead) and on kidneys (as a result of
cadmium, see orange and blue-orange hatched bars in figure) was established.
Effects on birth weight and (pubertal) development (PFOA) and cancer effects
(HCB) cannot be excluded for a percentage of examined participants. In the case
of PCBs, no effects on neurological and motor development are likely to be
expected for the majority of the examined adolescents. At population level,
lifelong exposure to current arsenic values poses an extra risk of developing
cancer (lung/bladder/skin cancer).
Uncertainty about health risks: minimal exposure is always
The assessment of health risks is not straightforward.
Scientific bodies sometimes use different health based benchmarks (HBBs). The
difference between the lowest and the highest health based benchmark
illustrates this uncertainty (the blue-orange hatched bars in the figure show
this for cadmium). Furthermore, the information for the deduction of reliable HBBs
is not always available. For PFOA, for example, research into the health
effects is still under development, and for HCB better health based benchmarks
are needed to assess the effect on cancer. For lead there is no safe value
where exposure is not associated with effects on intelligence. It is therefore
preferable to keep exposure to pollutants as low as possible.
How to avoid exposure and health effects?
Preventive measures, mainly
in hotspot areas
To limit exposure, and therefore the risk of health effects,
preventive measures in hotspot areas such as the Northern Campines (heavy
metals) remain recommended. Information and tips on how to enjoy your vegetable
garden in a safe and healthy manner are available via the campaign http://www.gezonduiteigengrond.be). Tips on healthy building and renovation are available at www.lne.be/bouw-gezond.
Attention for sensitive
Some subgroups in the population are more sensitive to
exposure to pollutants than others. Children, for example, more often put their
hands in their mouth and thus have a higher risk of lead exposure by swallowing
dust or soil particles. Other sensitive groups are infants, babies, women of
child-bearing age, sick and elderly people. Specific attention is paid to
socio-economically more vulnerable target groups.
follow-up and study needed for policy underpinning
Follow-up of the time trends is crucial to evaluate how the
exposure to pollutants evolves, and whether pollutants such as arsenic and PFOA
decrease in humans. In addition, a broader discussion with experts and
policymakers on the health based benchmarks to be used and acceptable health
risks is needed. The fourth Flemish human biomonitoring programme runs from
2016 to 2020 and, in addition to monitoring time trends, focuses on new
substances in the environment (www.milieu-en-gezondheid.be).
Figure: Evolution of
cadmium exposure in Flemish adolescents, and interpretation based on effects on
(FLEHS I-III, 2002-2015)
o Read the full
report ‘Development of environmental health indicators based on Human Biomonitoring results in Flanders’ (PDF, 3 MB) (Dutch report with English summary)
o MIRA indicator Lood in navelstrengbloed van pasgeborenen
o MIRA indicator Cadmium in bloed van jongeren
o MIRA indicator Arseen in urine van jongeren
o MIRA indicator Polychloorbifenylen in serum van jongeren
o MIRA indicator Hexachloorbenzeen in serum van volwassenen
o MIRA indicator Perfluoroctaanzuur in navelstrengserum van pasgeborenen
o MIRA indicators Milieu, Mens en Gezondheid
info at: Flemish Center of Expertise on Environment and Health
contact: Floor Vandevenne (firstname.lastname@example.org)