Pregnancy and the early years of life are well recognized to be periods of high susceptibility to environmental damage with lifetime consequences. We recently published the first study to determine the exposure to a large number of contaminants in mothers- and their children- from six European countries: Norway, Greece, Spain, France, Lithuania and the United Kingdom.
We recently published the first study to determine the exposure to a large number of contaminants in mothers- and their children- from six European countries
These results are part of The Human Early Life Exposome (HELIX) Project, funded by the European Commission. Coordinated by ISGlobal together with 13 European partners, the project aims to characterise the early-life exposome by combining many environmental hazards that mothers and children are exposed to, and link this to the children’s health, growth and development.
What were our main findings?
This study considering 45 chemicals is one of the first large-scale descriptions of the chemical exposome in European children.
This study considering 45 chemicals is one of the first large-scale descriptions of the chemical exposome in European children
We considered many families of chemicals, including some where health effects are suspected or plausible. These are:
- metals (including lead and mercury)
- phenols (including bisphenols A, triclosan, parabens)
- phthalates (such as DEHP)
- persistent organic pollutants (such as PCBs and DDT)
- organophosphate pesticides ((global exposure measured to pesticides for example diazinon)
- parathion, malathion or terbufos, still used in anti-lice lotion))
- perfluoroalkyl substances (including PFOS and PFOA)
- flame retardants (PBDEs).
We found that children across Europe are exposed to a wide range of contaminants in fetal life and childhood, but that their exposure varies by country and compound.
Most of the contaminants were found in almost all the participants, but less than one per cent of the samples had levels that exceeded current recommended thresholds for increased risk of adverse effects. However, for mercury and two perfluoroalkyl substances (PFOS and PFOA), many of the participants had concentrations that exceeded the threshold for which a reduction in exposure is recommended.
Any particular differences between countries?
The levels varied a lot between the six countries, which shows that country of residence is a strong determinant of your personal exposure. However, we noted that the groups studied are not necessarily representative of their populations.
The levels varied a lot between the six countries, which shows that country of residence is a strong determinant of your personal exposure
We think that the differences between countries can be explained by differences in diet and food contamination, use of consumer products and toiletries, indoor contamination as well as duration of breastfeeding.
In addition, national bans of certain chemicals and different country-specific product formulations play a role. For example, bisphenol A was banned from all food-contact materials in 2015 in France. Accordingly, we observed lower concentrations of bisphenol A in children from the French cohort, as compared to other cohorts.
What about Spain?
The levels of monoethyl phthalate (MEP, sourced mainly in plastics and fragrances) and parabens (in personal care products, food additives) in Spanish children were among the highest in the study. These compounds are found in high abundance in our environments. For example MEP, which was the dominating compound in children urine samples, is derived from the degradation of compounds (diethyl phthalate) found mostly in fragrances used in personal care products but also in indoor air. However, Spanish children had lower levels of other contaminants such as the heavy metal cadmium, compared to the other children in this study.
The Spanish mothers had also the highest median levels of MEP (phtalate) and four parabens. In addition, triclosan another compound used in personal care products, in particular found in toothpaste, was much higher in the Spanish mothers.
Mercury was also higher in children and mothers from the Spanish population. This contaminant is present in fish, and Spanish children were among those with higher fish consumption. Chronic exposure to methylmercury (MeHg), the most toxic organic form of mercury, is related to slower cognitive development. However, fish is the primary source of nutrients considered to improve child development, such as omega-3 fatty acids, so the balance between the benefits and risks of fish consumption has yet to be fully elucidated.
Any differences between mothers and their children?
Concentrations in samples from mothers were usually higher than in samples from children, except for one relatively new phthalate and bisphenol A, likely due to their recent introduction into the market. For compounds that remain in the body for a long time, for example PCBs and perfluoroalkyl substances, it is expected that mothers have higher levels than their children. For these compounds, we observed high correlations between levels in mothers and their children, showing that maternal exposure is decisive for the child’s levels many years after birth.
What does this mean?
The results highlight the need for frequent and harmonised surveillance to monitor levels of known contaminants and to detect any new ones as early as possible. In this regard, a good initiative is the Human Biomonitoring Initiative for Europe (HBM4EU) involving Spain and 27 other countries.
The results highlight the need for frequent and harmonised surveillance to monitor levels of known contaminants and to detect any new ones as early as possible
Regarding perfluoralkyl substances, the best way to reduce exposure to PFOS and PFOA is to prohibit their use. The amount of these contaminants in consumer products, diet and surroundings will eventually diminish. There is already a global ban against PFOS, and a ban for PFOA is in progress. There is also an international treaty to protect people and the environment from the harmful effects of mercury.