Recently, Gregory G. Bond from Northport, USA, and Daniel R. Dietrich from the University of Konstanz have contributed a comprehensive review about human cost burden of endocrine disrupting chemicals (Bond and Dietrich 2017). The authors critically discuss a recently published series of publications that claim that human exposure to endocrine disrupting chemicals cause substantial disease burdens and consequently cost society hundreds of billions of dollars per year (Trasande et al. 2015; Bellanger et al. 2015; Hauser et al. 2015; Legler et al. 2015; Hunt et al. 2016; Trasande et al. 2016; Attina et al. 2016). The largest fractions of these costs are based on the assumption that human exposure to organophosphate pesticides and brominated flame retardants cause ‘loss of IQ’.

The authors critically discuss the possible causal relationship and come to the conclusion that currently available evidence does not support a casual association with adverse neurodevelopmental and neurobehavioural outcomes in infants and children (Roth and Wilks 2014; Kim et al. 2014; Bond and Dietrich 2017). The main criticism includes incomplete control of confounding variables, weak and inconsistent findings in studies with small population sample sizes, uncertainties of exposure characterization and the lack of dose–response relationships. The authors conclude that the postulated causal relationship between endocrine disrupting chemical and disease burden is not supported by the available data. Therefore, the assigned disease burden costs lack scientific evidence (Bond and Dietrich 2017).

In recent years, endocrine active compounds have been a major focus in toxicological research (Hanioka et al. 2016; Van Esterik et al. 2016; Eisenbrand and Gelbke 2016; Niaz et al. 2015; Hengstler et al. 2011). Considering the high number of publications in this field with partially contradicting messages (Chen et al. 2015; Mansour et al. 2016; Wang et al. 2014; Harada et al. 2016; Dietrich and Hengstler 2016), systematic reviews on the weight of scientific evidence are of high value. In conclusion, currently not sufficient evidence is available to claim a causal relationship between environmental human exposure to organophosphates, as well as brominated flame retardants and reduced intelligence of children. For future studies in this field, it will be particularly important to study sufficiently large cohorts and control for possible confounding factors.