UmweltPerspektiven 5/2019

Sustainable chemistry: Quality of life and security for humans and the environment

Prof. Rolf Altenburger

Prof. Dr. Rolf Altenburger
Head of the Research Unit Chemicals in the Environment and of the Department of Bioanalytical Ecotoxicology

He is a biologist and Head of the Research Unit Chemicals in the Environment and of the Department of Bioanalytical Ecotoxicology at the UFZ in Leipzig. He is also a Professor at the Institute for Environmental Research at RWTH Aachen University. Professor Altenburger is spokesperson for the UFZ core subject area "Chemicals in the Environment" in the Helmholtz "Terrestrial Environment" programme. His research focusses on the analysis of the action of chemicals in the environment, the predictability and assessment of the effect of substance combinations and on establishing methods for measuring bioanalytical processes. He was appointed by Christian Schmidt, Federal Minister of Food and Agriculture, to serve on the Scientific Advisory Board "National Action Plan for the Sustainable Use of Pesticides" from 2015 to 2018.

Today, humans largely determine the conditions under which they live together and with their environment. This shaping power was and is not least associated with the innovative use of chemicals. Chemical services played a major role in increasing agricultural productivity, improving food security, revolutionizing the life-extending handling of diseases and thereby supported an enormous growth in population. Following the arguments of US psychologist Steven Pinker on the development of forms of social organisation, such extension of human possibilities has also substantially reduced levels of violence between people worldwide and according to analyses by the World Bank decreased extreme poverty substantially.

Since the report by the Club of Rome in 1972, we have debated planetary limits, i.e. threshold values that must not be violated.

The depth of human intervention by our actions has simultaneously increased on the global scale. Since the report by the Club of Rome in 1972, we debate planetary limits, currently understood as threshold values that must not be violated. The global dimension of human activity is now being approached more quickly than in the past, whether through the sheer number of people, such as in their individual housing or mobility requirements, or through the dimension of technological hazard potentials, such as in the energy or bio economy sector.

Emerging risks are tackled in modern societies using increasingly sophisticated expert systems. Initially, it was primarily disasters that resulted in scientifically-backed assessments and recommendations for action. These included chemical accidents such as in Bhopal, India or in Seveso, Italy, in which many people were killed or injured, fires and oil tanker accidents with devastating effects on nature, or drug scandals such as the thalidomide scandal, which resulted in massive damage to the health of many thousands of children. The public expectation these days is that science should forecast any unwanted effects of new substances, products, technologies or processes on humans and the environment before they are even introduced or marketed.

The public expects science to forecast effects on humans and the environment.

We have everyday experience with forecasts when it comes to the weather: We, on a daily basis, orient ourselves accordingly and at the same time know that the forecast may be imprecise or even wrong. Forecasting methods are the subject of much discussion within science and increasingly their results are picked up in public debates. A major dilemma of current debates regarding chemical safety becomes apparent when e.g. a group of pulmonary physicians publicly casts doubt on the scientific validity of a specified limit for an air pollutant, here nitrogen dioxide, which led to restrictions for use of private cars in cities. There might be a contentious scientific core of the debate but also the legitimacy of specialized expert knowledge can be questioned at any time by 'alternative' experts or experts from other fields.

The transparency of public debate is praiseworthy, as only in this way can factual errors, here that of the pulmonary physicians, be brought to light. In this case, however, it was also a phantom debate anyhow to speculate whether a child walking along a busy road would have to smoke cigarettes regularly for 30 days or 30 years to be exposed to a comparable health risk. Firstly, it is ambivalent to compare risks that individuals can choose to risks that are imposed ("Don't make a fuss, after all, you are taking a greater risk when you go skiing or ride a bicycle"). Next the assumptions are free from a meaningful context as no child exposed to pollution through a busy road experiences individual compounds only as they are not equipped with particulate and ozone filters to cut out all additional exposures. Contrary to the assumptions in many heated debates on safety thresholds for toxicants, there is hardly ever isolated exposure to individual chemicals. Moreover, the public is not willing to accept any longer that verifiable harm to humans must first have been documented before action is taken. Thus, there are mismatches between public expectations for securing chemical safety and established expert approaches.

Established expert debates focussing on individual chemicals and defined uses, regardless of whether they are called glyphosate, fipronil or nitrogen oxide, therefore typically fall short of public demand. And therein lie the true challenges for science and rational measures. Currently, a forecast of undesirable effects is largely sector-based. For example, we evaluate the harmful potential of a new pesticide, cosmetic or wall paint in isolation. Obtaining the required information is a more or less laborious and follows established workflows. However, if the goal is prevention oriented, this approach is disconnected from actual people and specific environments. The dimensions of any possible use are also essentially unknown in prospective assessments, as they lie in the future. Finally, we know from many observations that protection targets such as human health or biodiversity are challenged by multiple exposures against mixtures of substances and other stressors. These can be diverse and may also change significantly over time.

An attempt to capture this complexity comes with the term 'exposome' invented in health and environmental sciences. The purpose of exposome research is to account for the sum of all environmental influences to which individuals are exposed over their lifetime and to examine their significance for the incidence of disease. Exposome borrows from the term genome, as scientific research has long focused on a comprehensive analysis of the genetic causes of diseases. However, it is consented that genetic predisposition can only explain a small fraction of diseases. The much larger part is now considered to be due to environmental factors meaning that these are in principle preventable. Investigation of the exposome therefore is a promising new approach in environmental and health research. It addresses a wide range of influencing factors that can contribute to a disease and specifically targets multiple exposure to toxicants over extended periods of time. It strives to provide concepts of how observations in populations can be causally linked to knowledge about the environmental behaviour of chemicals.

Our goal is to systematically register and to establish a forward-looking evaluation of the wide range of chemicals to which the environment and people are exposed.

At the UFZ, we therefore develop a one health perspective to connect human and environmental health research approaches. Our goal is to provide novel tools for systematic monitoring of pollution and to establish forward-looking perspectives for the wide range of chemicals, the chemical universe, to which both the environment and people are exposed. We will focus particularly on children and vulnerable environments, who react sensitive to environmental factors. This ambition requires long-term endeavours and networking with complementary partners. These efforts promise significant insights for the urgently necessary advancement of chemical assessment. It would enable us to identify modern options for the knowledge-based management of fluctuating and complex stressors for people and the environment. In other words: We seek to provide fundamental progress for the nexus of sustainable chemistry, quality of life and safety.