…in case you didn’t already know that. Risk assessments and reasoned analyses are only as valid as the soundness, relevance and measurability of the evidence they are based upon. Environmental toxicology and chemistry continues to veer further away from science-based chemistry and toxicology.
The January issue of Wiley’s Environmental Toxicology and Chemistry highlights its special section on global climate change. According to the editors-in-chief, the issue “represents the consensus findings of 36 invited scientists from 11 countries on a very important, challenging, and timely topic.”
The papers published in this issue came from the SETAC international workshop called “The Influence of Global Climate Change on the Scientific Foundations and Applications of Environmental Toxicology and Chemistry” held on December 18, 2012. Wiley’s media release says:
The papers tackle the impacts of global climate change on chemical contaminants, organism acclimation and vulnerable communities as important considerations for future assessments of human and ecological risk. They address the need to consider all potential consequences, while accounting for the magnitude and duration of anticipated impacts in combination with the nature and severity of a changing climate. Practitioners must also overcome the challenges of continually shifting baseline conditions while estimating the extent of injury to resources and the extent of restoration needed as a result of the chemical effects from climate change.
The introductory paper noted the working premise of the workshop attendees:
Global climate change (GCC) is a powerful advancing force that can impact ecosystems and humans for decades to come. It is likely that GCC will manifest as a suite of stressors, or a syndrome, impacting the abiotic, biotic, and socioeconomic components of the landscape. It is possible that changes in stressor regimes and the potential for toxic effects will occur, as well as a need to revise assumptions about past conditions being models for current and future conditions. In addition, changes in current methods and a reexamination of predictions and predictive tools for the fate and transport of chemical stressors that are built on those assumptions will be needed. These points are particularly important as the chemical fate and dynamics data are critical for the performance of human health risk assessment and ecological risk assessments as well as the practice of damage assessment and restoration of natural resources in the United States and Europe…
Not surprisingly, the key findings from the workshop were:
The effects of GCC on the occurrence, fate, and distribution of chemicals are anticipated to result in changes in exposures. These include the potential for increased global transport of dust and pollution, increased erosion of soil and mobilization of legacy contaminants, alterations in the deposition and volatilization of chemicals, and altered flood and drought frequency and magnitude. Indirect effects have the potential to significantly modify the magnitude and temporal exposure to chemical contaminants….
Greater exposures to chemicals in the environment because of GCC were also presumed to be significant risks to human health:
Direct toxic effects range from acute poisonings and triggering of acute events like cardiac arrhythmias and asthma attacks to chronic effects like cancer and immunosuppression. Indirect effects include changes in health risks associated with changes in food supply and water sources as a result of chemical contamination or due to the selection of antibiotic resistance traits in bacteria exposed to veterinary and human antibiotics, metals, and other toxic substances. Because the persistence and mobility of toxic chemicals in the environment are affected by weather conditions such as temperature, precipitation, and wind, changes in these processes associated with GCC have implications for human exposures. Also, GCC is predicted to affect human diseases, change behavioral patterns that could influence exposures, and create additional physiologic stress through extreme temperatures. These human impacts of GCC, in addition to affecting health directly, may affect the vulnerability of humans to health risks from chemical exposures. Together, these changes in exposure and vulnerability to toxic chemicals may significantly alter human health risks…
The authors concluded by calling for heightened surveillance of chemicals and health on a global level, revised data and computer models, and more research funding:
A concerted effort is therefore needed at an international level to better characterize the potential impacts of GCC and other future drivers on exposure, sensitivity, and risk. We recommend that work should focus on the following areas. First, the development of future models and scenarios of land use and social, technological, and economic change in order to provide a basis for informing how inputs of chemicals to the environment, in different regions of the world, may change in the future. Second, work should focus on the generation of improved data sets and models for determining future human exposure to chemicals in different environmental matrices. This work should consider the importance of emerging exposure pathways, such as increased inhalation of contaminated dust or exposure consequences of flooding, and consider the implications of human behavioral change on the degree of exposure. Furthermore, there should be focus the development of research programs that aim to fill gaps in our understanding of the interactions between climate and weather parameters and human sensitivity to chemical exposures. Focus should also be given to the refinement of regulatory models and procedures in the light of knowledge gained from work on exposure and human sensitivity to toxicants. Existing risk assessments and chemical management programs should also be updated to determine whether the risks of a current-use product could change in the future. Finally, work should give focus to the development of targeted surveillance schemes for the presence and health effects of select chemicals in different environmental compartments for different regions of the world and at smaller geographical scales to address inequities at the community level.
The full issue is available here: