2nd update on the report on opportunities and obstacles of combining HBM and health studies, availability of health studies and administrative registers and guidelines. Deliverable Report D11.4

Many environmental substances (chemicals and heavy metals) are associated with adverse health effects such as increased risk of cardiovascular disease, several types of cancer, metabolic syndrome, asthma, chronic obstructive pulmonary disease, neurological disorders, problems with kidney and liver function, reproductive health problems and cognitive development. Therefore, it is essential to be able to monitor the human exposure levels to such substances and their associations to health.

In order to demonstrate possible adverse health effects of chemical exposures on human health, it is important to obtain both exposure and health information among the same individuals. Chemical exposures to humans are usually measured using Human Biomonitoring studies (HBM). These studies often include some health information mainly obtained through self-reported questionnaire(s). Self-reported health information could suffer from reporting bias, as well as awareness bias. People do not necessarily remember which diseases they have been diagnosed with and when, which leads to reporting bias. They may also be unaware of their health condition, as many diseases can be asymptomatic for a long time, which again leads to awareness bias.

More extensive health information could be obtained through health examination surveys which include also objective health measurements. In some of the HBM4EU partner countries, HBM studies have been combined with health examination surveys. There are several countries which have health surveys without a HBM module. The principal investigators of these health surveys report that in most cases it would be possible to add an HBM module to their health survey even though several potential obstacles for this type of combination were identified.

An alternative way to obtain improved health information on HBM participants is to link individual HBM data to existing administrative registers on health such as a cause of death registers or hospitalisation data. This is not possible in all countries due to lack of common identifiers between different data sources or due to legal restrictions within the country. But in the countries where this can be done, such as in the Nordic countries, this is a cost-effective way to obtain information on both disease history and disease onset (disease incidence) based on the diagnoses registered in the health register data. Nevertheless it is important to be aware of that data from administrative registers may not be complete, but are limited to only those who seeked medical care for their symptoms or disease.

Although a lot of evidence already exists on adverse health effects due to exposure to environmental chemicals, there are still large knowledge gaps. Because an experimental study in humans is unethical in most cases, the evidence has to heavily rely on observational studies. Thus, more studies of high quality are needed, including a large sample size and with standardised methods of measurement chemical exposures and health outcomes. The use of standardised operating protocols is essential to ensure high quality and comparability of the results across studies.