| NECTAR: Network for environmental chemical toxicants affecting reproduction

The NECTAR cluster was launched in 2008 to investigate the potential impact of environmental chemicals and pollutants on reproductive health. Endocrine disrupters are natural and man-made substances, such as compounds used in plastics and pesticides, to which we are exposed every day and which can mimic or interfere with our hormones. This may pose risks especially for the developing foetus and may reduce its future reproductive potential.

The NECTAR cluster (coordinated by Professor Andreas Kortenkamp from the University of London) is an international collaboration that has been awarded €12.4 million to investigate the potential impact of chemicals on reproductive health. NECTAR is made up of four projects: REEF, DEER, CONTAMED and CLEAR, all of which aim to investigate the long-term health impacts of endocrine-disrupting chemicals.

Reproductive effects of environmental chemicals in females

REEF (coordinated by Professor Paul Fowler, University of Aberdeen, UK), utilises sheep and mice in order to clarify links between the exposure of the female during foetal development, her reproductive capacity as an adult and the extent to which damage is passed on to her own young. Sheep exposed to sewage-sludge-treated pastures provide a model of real-life exposure to a broad range of environmental chemicals at low concentrations. Long-lived and sharing many reproductive similarities with humans, sheep are a valuable model for the study of the impact of environmental pollutants. In the past, many studies have focused on single or only small numbers of chemicals, at relatively high doses, which were tested on short-lived rodent species. Such patterns of exposure to chemicals are completely different from the way in which humans are exposed, and work with sheep offers the opportunity to better understand the risks posed by man-made chemicals.

Developmental effects of environment on reproductive health

DEER (coordinated by Professor Jorma Toppari, University of Turku, Finland), focuses on male reproductive health problems. The most common disorders of male reproductive health in newborn (cryptorchidism, i.e. undescended testes and hypospadias i.e. abnormally placed urinary opening) and young adults (low sperm counts, testis germ cell cancer) have their origin in foetal life. Together, these reproductive disorders form the testicular dysgenesis syndrome (TDS), and its incidence is on the rise in Europe. Common environmental chemicals might contribute to TDS, and DEER will use novel bioinformatics approaches to investigate this idea. Because of the long latency (up to 40 years) between cause (in foetal life) and health consequences and the enormous complexity of the ever-changing chemical mixtures that humans are exposed to during their life, these scenarios cannot be reproduced in the laboratory. Therefore, computer-aided systems biology and bioinformatics approaches, using data obtained from human studies, will be used for assessing exposure-outcome associations based on real-life exposure scenarios.

Contaminant mixtures and human reproductive health - novel strategies for health impact and risk assessment of endocrine disrupters

CONTAMED (coordinated by Professor Andreas Kortenkamp, The School of Pharmacy, University of London, UK), focuses on the development of biomarkers for combined exposures of chemicals and long-term delayed effects of chemical cocktails. At present, individual substances cannot be shown to contribute to adverse effects at relevant exposure levels; however, people are typically exposed to multiple chemicals simultaneously. There are indications that combinations of chemicals may play a cumulative role and adverse health effects in boys were also linked to widely used plasticisers, pesticides and other environmental chemicals found in mothers’ milk and urine. To substantiate these findings the focus of the CONTAMED project lies in the use of cutting-edge chemical analytical techniques and bio-monitoring approaches to analyse human-tissue specimens from existing mother-child cohorts.

Climate change, environmental contaminants and reproductive health

Finally, CLEAR (coordinated by Professor Jens Peter Bonde, Aarhus University Hospital, Denmark), which only recently joined the Nectar cluster, aims to increase the limited knowledge on links between parental blood levels of environmental contaminants and reproductive health outcomes in terms of functional and biological measures of fertility, child development (growth, developmental milestones, attention deficit hyperactivity syndrome (ADHS) and obesity in children aged 4–6 years). This work relies on a large existing parent-child cohort where a follow-up survey provides new crucial data. Together with information on climate-induced changes in contaminant mobility and distribution, this data will provide insights into possible future risk scenarios related to global climate change.

Overall objectives

The NECTAR cluster aims to foster interactions between the four projects with the aim of providing the knowledge necessary to set the scene for environmentally relevant human health exposure studies. The cluster’s ultimate goal is to contribute to improvements in regulatory chemical safety assessment in Europe.

Contact: Professor Andreas Kortenkamp (email: andreas.kortenkamp@pharmacy.ac.uk) and Dr Erika Rosivatz (email: erika.rosivatz@pharmacy.ac.uk), The School of Pharmacy, University of London, London (UK).

Further information can be found on the following websites:

The CLEAR website is under construction.