Author: Markus Quante
Publisher: Springer Science & Business Media
ISBN: 3642174191
Category : Science
Languages : en
Pages : 417
Book Description
This book evolved from the 5th School of Environmental Research entitled „Persistent Pollution – Past, Present and Future", which has set a focus on Persistent Organic Pollutants (POPs), heavy metals and aerosols. - reconstruction of past changes based on the scientific analysis of natural archives such as ice cores and peat deposits, - evaluation of the present environmental state by the integration of measurements and modelling and the establishment of cause-effect-patterns, - assessment of possible environmental future scenarios including emission and climate change perspectives.
Persistent Pollution – Past, Present and Future
Author: Markus Quante
Publisher: Springer Science & Business Media
ISBN: 3642174191
Category : Science
Languages : en
Pages : 417
Book Description
This book evolved from the 5th School of Environmental Research entitled „Persistent Pollution – Past, Present and Future", which has set a focus on Persistent Organic Pollutants (POPs), heavy metals and aerosols. - reconstruction of past changes based on the scientific analysis of natural archives such as ice cores and peat deposits, - evaluation of the present environmental state by the integration of measurements and modelling and the establishment of cause-effect-patterns, - assessment of possible environmental future scenarios including emission and climate change perspectives.
Publisher: Springer Science & Business Media
ISBN: 3642174191
Category : Science
Languages : en
Pages : 417
Book Description
This book evolved from the 5th School of Environmental Research entitled „Persistent Pollution – Past, Present and Future", which has set a focus on Persistent Organic Pollutants (POPs), heavy metals and aerosols. - reconstruction of past changes based on the scientific analysis of natural archives such as ice cores and peat deposits, - evaluation of the present environmental state by the integration of measurements and modelling and the establishment of cause-effect-patterns, - assessment of possible environmental future scenarios including emission and climate change perspectives.
Air Pollution in the 21st Century
Author: T. Schneider
Publisher: Elsevier
ISBN: 0080544908
Category : Science
Languages : en
Pages : 1113
Book Description
This symposium was jointly organized by the United States Environmental Protection Agency and The Netherlands Ministry of Housing, Spatial Planning and the Environment. These proceedings will provide a stimulus for taking up the challenges of environmental policy development in the 21st century, and will contribute to continuing co-operation.Clean air is a basic condition for health. Air pollution aggravates respiratory problems, leading to increased sickness absenteeism, increased use of health care services and even premature mortality. Air pollution is under intensive discussion in the United States and Europe.In The Netherlands, a wide range of policy instruments have been formulated which have reduced air pollution. For example; since 1975, sulphur dioxide and lead emissions have been reduced. However, emission reduction figures for many other substances are more modest. Many air pollution problems persist because progress in countering these problems is nullified by growth in the economy and traffic. Another important target is the prevention of climate change. The international community is agreed that the increasing concentration of greenhouse gases in the atmosphere has led to a gradual increase in the earth's temperature. In terms of the environmental consequences and social implications, the greenhouse problem surpasses all other air quality problems.Across Europe, strategies are being developed to reduce acidification and photochemical air pollution. An air emission ceiling for each country in the European Union is being agreed. In the area of climate change, there is good co-operation between the United States, The Netherlands and other EU Members States in the ongoing global negotiations. This is the start of a new movement. In the last century economies and societies developed through increasing human productivity. In the next century they must develop through increasing the productivity of fuel and natural resources.
Publisher: Elsevier
ISBN: 0080544908
Category : Science
Languages : en
Pages : 1113
Book Description
This symposium was jointly organized by the United States Environmental Protection Agency and The Netherlands Ministry of Housing, Spatial Planning and the Environment. These proceedings will provide a stimulus for taking up the challenges of environmental policy development in the 21st century, and will contribute to continuing co-operation.Clean air is a basic condition for health. Air pollution aggravates respiratory problems, leading to increased sickness absenteeism, increased use of health care services and even premature mortality. Air pollution is under intensive discussion in the United States and Europe.In The Netherlands, a wide range of policy instruments have been formulated which have reduced air pollution. For example; since 1975, sulphur dioxide and lead emissions have been reduced. However, emission reduction figures for many other substances are more modest. Many air pollution problems persist because progress in countering these problems is nullified by growth in the economy and traffic. Another important target is the prevention of climate change. The international community is agreed that the increasing concentration of greenhouse gases in the atmosphere has led to a gradual increase in the earth's temperature. In terms of the environmental consequences and social implications, the greenhouse problem surpasses all other air quality problems.Across Europe, strategies are being developed to reduce acidification and photochemical air pollution. An air emission ceiling for each country in the European Union is being agreed. In the area of climate change, there is good co-operation between the United States, The Netherlands and other EU Members States in the ongoing global negotiations. This is the start of a new movement. In the last century economies and societies developed through increasing human productivity. In the next century they must develop through increasing the productivity of fuel and natural resources.
Global Sources of Local Pollution
Author: National Research Council
Publisher: National Academies Press
ISBN: 0309144019
Category : Nature
Languages : en
Pages : 248
Book Description
Recent advances in air pollution monitoring and modeling capabilities have made it possible to show that air pollution can be transported long distances and that adverse impacts of emitted pollutants cannot be confined to one country or even one continent. Pollutants from traffic, cooking stoves, and factories emitted half a world away can make the air we inhale today more hazardous for our health. The relative importance of this "imported" pollution is likely to increase, as emissions in developing countries grow, and air quality standards in industrial countries are tightened. Global Sources of Local Pollution examines the impact of the long-range transport of four key air pollutants (ozone, particulate matter, mercury, and persistent organic pollutants) on air quality and pollutant deposition in the United States. It also explores the environmental impacts of U.S. emissions on other parts of the world. The book recommends that the United States work with the international community to develop an integrated system for determining pollution sources and impacts and to design effective response strategies. This book will be useful to international, federal, state, and local policy makers responsible for understanding and managing air pollution and its impacts on human health and well-being.
Publisher: National Academies Press
ISBN: 0309144019
Category : Nature
Languages : en
Pages : 248
Book Description
Recent advances in air pollution monitoring and modeling capabilities have made it possible to show that air pollution can be transported long distances and that adverse impacts of emitted pollutants cannot be confined to one country or even one continent. Pollutants from traffic, cooking stoves, and factories emitted half a world away can make the air we inhale today more hazardous for our health. The relative importance of this "imported" pollution is likely to increase, as emissions in developing countries grow, and air quality standards in industrial countries are tightened. Global Sources of Local Pollution examines the impact of the long-range transport of four key air pollutants (ozone, particulate matter, mercury, and persistent organic pollutants) on air quality and pollutant deposition in the United States. It also explores the environmental impacts of U.S. emissions on other parts of the world. The book recommends that the United States work with the international community to develop an integrated system for determining pollution sources and impacts and to design effective response strategies. This book will be useful to international, federal, state, and local policy makers responsible for understanding and managing air pollution and its impacts on human health and well-being.
Marine Pollution: Current Status, Impacts and Remedies
Author: De-Sheng Pei
Publisher: Bentham Science Publishers
ISBN: 9811412685
Category : Science
Languages : en
Pages : 500
Book Description
While oceans are vast, they represent a fragile resource that must be protected if we want to protect our livelihoods and our planet. Marine pollution has been a topic of concern for a long time, and it has recently attracted the attention of scientists, environmentalists, economists, politicians and journalists in mainstream media. Besides providing food, transportation routes and other resources, the oceans serve as a heat absorbing sink which offsets the extreme heating effects of climate change, but only to a limited degree. Pollution in marine environments such as the oceans, poses a threat to coastal communities by affecting the fauna and flora in the environment and the health of the nearby population. This has a disruptive effect on the health and economy of these communities. Marine Pollution: Current Status, Impacts and Remedies emphasizes the limitations of marine resources that relevant environments provide. Readers will find chapters on methods to assess pollution as well as important information for identifying, measuring, and remediating various pollutants. The book also covers some known pollutants (heavy metals, organic pollutants, microplastics) and ways to manage these substances. Other issues covered in the book include problems caused by invasive species, and the ecological problems caused by pollutants which affect local fauna and flora. This book will prove to be a useful resource for students, researchers, and policymakers, who are working in environmental science, marine conservation and allied fields. [Series Intro] Marine Ecology: Current and Future Developments brings forth contemporary issues in the study of marine environments. The scope of the series includes ecological, toxicological and biological aspects of the topic. Each volume of the series focuses on a broad theme, with reviews contributed by several experts in the field. The series is essential reading for environmental scientists, ecologists, conservationists and marine biologists.
Publisher: Bentham Science Publishers
ISBN: 9811412685
Category : Science
Languages : en
Pages : 500
Book Description
While oceans are vast, they represent a fragile resource that must be protected if we want to protect our livelihoods and our planet. Marine pollution has been a topic of concern for a long time, and it has recently attracted the attention of scientists, environmentalists, economists, politicians and journalists in mainstream media. Besides providing food, transportation routes and other resources, the oceans serve as a heat absorbing sink which offsets the extreme heating effects of climate change, but only to a limited degree. Pollution in marine environments such as the oceans, poses a threat to coastal communities by affecting the fauna and flora in the environment and the health of the nearby population. This has a disruptive effect on the health and economy of these communities. Marine Pollution: Current Status, Impacts and Remedies emphasizes the limitations of marine resources that relevant environments provide. Readers will find chapters on methods to assess pollution as well as important information for identifying, measuring, and remediating various pollutants. The book also covers some known pollutants (heavy metals, organic pollutants, microplastics) and ways to manage these substances. Other issues covered in the book include problems caused by invasive species, and the ecological problems caused by pollutants which affect local fauna and flora. This book will prove to be a useful resource for students, researchers, and policymakers, who are working in environmental science, marine conservation and allied fields. [Series Intro] Marine Ecology: Current and Future Developments brings forth contemporary issues in the study of marine environments. The scope of the series includes ecological, toxicological and biological aspects of the topic. Each volume of the series focuses on a broad theme, with reviews contributed by several experts in the field. The series is essential reading for environmental scientists, ecologists, conservationists and marine biologists.
Emerging Contaminants in the Environment
Author: Hemen Sarma
Publisher: Elsevier
ISBN: 032385981X
Category : Science
Languages : en
Pages : 713
Book Description
Emerging Contaminants in the Environment: Challenges and Sustainable Practices covers all aspects of emerging contaminants in the environment, from basic understanding to different types of emerging contaminants and how these threaten organisms, their environmental fate studies, detection methods, and sustainable practices of dealing with contaminants. Emerging contaminant remediation is a pressing need due to the ever-increasing pollution in the environment, and it has gained a lot of scientific and public attention due to its high effectiveness and sustainability. The discussions in the book on the bioremediation of these contaminants are covered from the perspective of proven technologies and practices through case studies and real-world data. One of the main benefits of this book is that it summarizes future challenges and sustainable solutions. It can, therefore, become an effective guide to the elimination (through sustainable practices) of emerging contaminants. At the back of these explorations on sustainable bioremediation of emerging contaminants lies the set of 17 goals articulated by the United Nations in its 2030 Agenda for Sustainable Development, adopted by all its member states. This book provides academics, researchers, students, and practitioners interested in the detection and elimination of emerging contaminants from the environment, with the latest advances by leading experts in emerging contaminants the field of environmental sciences. - Covers most aspects of the most predominant emerging contaminants in the environment, including in soil, air, and water - Describes the occurrence of these contaminants, the problems they cause, and the sustainable practices to deal with the contaminants - Includes data from case studies to provide real-world examples of sustainable practices and emerging contaminant remediation
Publisher: Elsevier
ISBN: 032385981X
Category : Science
Languages : en
Pages : 713
Book Description
Emerging Contaminants in the Environment: Challenges and Sustainable Practices covers all aspects of emerging contaminants in the environment, from basic understanding to different types of emerging contaminants and how these threaten organisms, their environmental fate studies, detection methods, and sustainable practices of dealing with contaminants. Emerging contaminant remediation is a pressing need due to the ever-increasing pollution in the environment, and it has gained a lot of scientific and public attention due to its high effectiveness and sustainability. The discussions in the book on the bioremediation of these contaminants are covered from the perspective of proven technologies and practices through case studies and real-world data. One of the main benefits of this book is that it summarizes future challenges and sustainable solutions. It can, therefore, become an effective guide to the elimination (through sustainable practices) of emerging contaminants. At the back of these explorations on sustainable bioremediation of emerging contaminants lies the set of 17 goals articulated by the United Nations in its 2030 Agenda for Sustainable Development, adopted by all its member states. This book provides academics, researchers, students, and practitioners interested in the detection and elimination of emerging contaminants from the environment, with the latest advances by leading experts in emerging contaminants the field of environmental sciences. - Covers most aspects of the most predominant emerging contaminants in the environment, including in soil, air, and water - Describes the occurrence of these contaminants, the problems they cause, and the sustainable practices to deal with the contaminants - Includes data from case studies to provide real-world examples of sustainable practices and emerging contaminant remediation
Microbial Biotechnology
Author: Pankaj Chowdhary
Publisher: John Wiley & Sons
ISBN: 1119834457
Category : Science
Languages : en
Pages : 500
Book Description
A holistic approach covering a wide range of environmental microbial applications along with current and future trends In Microbial Biotechnology: Role in Ecological Sustainability and Research, a team of distinguished researchers delivers an authoritative overview of the role of microbial biotechnology in the pursuit of environmental and ecological sustainability. The book provides readers with compelling presentations of microbial technology, including its applications in the removal of environmental pollutants, and sustainable agriculture using microbial biocontrol agents or bio-fertilizers. Readers will also be able to explore the microbial reduction of greenhouse gases and a wide range of other cutting-edge applications, including the removal of various toxic environmental contaminants, such as antibiotics, pesticides, dyes, and heavy metals. Microbial Biotechnology provides: A thorough introduction to microorganisms, their metabolic engineering, the human microbiome, and other foundational topics An in-depth exploration of environmental management, including bioremediation through a nexus approach A fulsome treatment of current trends in microbial biotechnology and its role in sustainable production Perfect for professionals in applied microbiology, biotechnology, environmental engineering, green chemistry, and soil science, Microbial Biotechnology: Role in Ecological Sustainability and Research will also earn a place in the libraries of research scholars, scientists, and academicians with an interest in environmental microbiology and ecology.
Publisher: John Wiley & Sons
ISBN: 1119834457
Category : Science
Languages : en
Pages : 500
Book Description
A holistic approach covering a wide range of environmental microbial applications along with current and future trends In Microbial Biotechnology: Role in Ecological Sustainability and Research, a team of distinguished researchers delivers an authoritative overview of the role of microbial biotechnology in the pursuit of environmental and ecological sustainability. The book provides readers with compelling presentations of microbial technology, including its applications in the removal of environmental pollutants, and sustainable agriculture using microbial biocontrol agents or bio-fertilizers. Readers will also be able to explore the microbial reduction of greenhouse gases and a wide range of other cutting-edge applications, including the removal of various toxic environmental contaminants, such as antibiotics, pesticides, dyes, and heavy metals. Microbial Biotechnology provides: A thorough introduction to microorganisms, their metabolic engineering, the human microbiome, and other foundational topics An in-depth exploration of environmental management, including bioremediation through a nexus approach A fulsome treatment of current trends in microbial biotechnology and its role in sustainable production Perfect for professionals in applied microbiology, biotechnology, environmental engineering, green chemistry, and soil science, Microbial Biotechnology: Role in Ecological Sustainability and Research will also earn a place in the libraries of research scholars, scientists, and academicians with an interest in environmental microbiology and ecology.
Persistent Organic Pollutants in Aquatic Systems
Author: Tarek Othman Said
Publisher: Springer Nature
ISBN: 3031533410
Category : Organic water pollutants
Languages : en
Pages : 173
Book Description
This book addressed an in-depth comprehension of the classifications and characterizations of POPs, which have become global issues due to bioaccumulation, persistency, and toxicity. It represents the milestones of the development of pesticide application, industry, and management. Banned SC-POPs have special investigations. It discusses air-sea exchange, ocean currents, phase distribution, speciation, adsorption, desorption, and degradation as the key processes that control POP's fate. The book explores several aspects of POP chemistry that have a direct influence on their biochemical and toxicological consequences. The book illustrates the dynamic equilibriums influencing the proportion of a POP's gaseous, liquid, and solid phases. The book discussed POP migration by referring to the grasshopper effect. It also explores the impacts of climate change on emissions and the fate of POPs through a global-scale multimedia fate model. Additionally, it displays the impact of potential global change scenarios on POP bioaccumulation patterns. The book is directed at giving a deep discussion of the method's QA/QC process for POP determination and has verified the accuracy and precision of the procedures. As a distinctive point, it discusses many aspects concerning the toxicity of POPs. It reports mechanisms describing the toxicity of POPs on immune systems, carcinogenesis, endocrine, neural, and reproductive systems. The book keeps an eye on a model describing the global distribution and toxicity of PAHs. Among the exclusive points in the book is the evaluation of the recent ecological status in Egypt relative to POPs through a time-scale overview and recent case studies. It provides thematic literature related to DDC research in Africa through the WoS and Scopus databases from 1949 to 2021. The book emphasizes models for predicting the annual contribution rate of POPs as a way to raise public awareness about POPs. The greatest challenge for the book is how to motivate the audience to be aware of these hazardous materials in marine ecosystems. Moreover, this book will be of great interest to academics, professionals, practitioners, post-graduate students, and undergraduates because it gives a clear overview of POPs in the marine environment. It also provides decision-makers with a realistic perspective of the environmental file, allowing them to address environmental issues and directing stockholders to safer locations for environmental activity. From a future perspective, the regulation of pervasive POPs, with special reference to recently evaluated harmful substances (PFASs), has faced significant challenges in the wake of pressure from regulators.
Publisher: Springer Nature
ISBN: 3031533410
Category : Organic water pollutants
Languages : en
Pages : 173
Book Description
This book addressed an in-depth comprehension of the classifications and characterizations of POPs, which have become global issues due to bioaccumulation, persistency, and toxicity. It represents the milestones of the development of pesticide application, industry, and management. Banned SC-POPs have special investigations. It discusses air-sea exchange, ocean currents, phase distribution, speciation, adsorption, desorption, and degradation as the key processes that control POP's fate. The book explores several aspects of POP chemistry that have a direct influence on their biochemical and toxicological consequences. The book illustrates the dynamic equilibriums influencing the proportion of a POP's gaseous, liquid, and solid phases. The book discussed POP migration by referring to the grasshopper effect. It also explores the impacts of climate change on emissions and the fate of POPs through a global-scale multimedia fate model. Additionally, it displays the impact of potential global change scenarios on POP bioaccumulation patterns. The book is directed at giving a deep discussion of the method's QA/QC process for POP determination and has verified the accuracy and precision of the procedures. As a distinctive point, it discusses many aspects concerning the toxicity of POPs. It reports mechanisms describing the toxicity of POPs on immune systems, carcinogenesis, endocrine, neural, and reproductive systems. The book keeps an eye on a model describing the global distribution and toxicity of PAHs. Among the exclusive points in the book is the evaluation of the recent ecological status in Egypt relative to POPs through a time-scale overview and recent case studies. It provides thematic literature related to DDC research in Africa through the WoS and Scopus databases from 1949 to 2021. The book emphasizes models for predicting the annual contribution rate of POPs as a way to raise public awareness about POPs. The greatest challenge for the book is how to motivate the audience to be aware of these hazardous materials in marine ecosystems. Moreover, this book will be of great interest to academics, professionals, practitioners, post-graduate students, and undergraduates because it gives a clear overview of POPs in the marine environment. It also provides decision-makers with a realistic perspective of the environmental file, allowing them to address environmental issues and directing stockholders to safer locations for environmental activity. From a future perspective, the regulation of pervasive POPs, with special reference to recently evaluated harmful substances (PFASs), has faced significant challenges in the wake of pressure from regulators.
Soil Pollution
Author: Armando C. Duarte
Publisher: Academic Press
ISBN: 0128498722
Category : Science
Languages : en
Pages : 314
Book Description
Soil Pollution: From Monitoring to Remediation provides comprehensive information on soil pollution, including causes, distribution, transport, the transformation and fate of pollutants in soil, and metabolite accumulation. The book covers organic, inorganic and nanoparticle pollutants and methodologies for their monitoring. Features a critical discussion on ecotoxicological and human effects of soil pollution, and strategies for soil protection and remediation. Meticulously organized, this is an ideal resource for students, researchers and professionals, providing up-to-date foundational content for those already familiar with the field. Chapters are highly accessible, offering an authoritative introduction for non-specialists and undergraduate students alike. - Highlights the relevance of soil pollution for a sustainable environment in chapters written by interdisciplinary expert academics and professionals from around the world - Includes cases studies of techniques used to monitor soil pollution - Includes a chapter on nanoparticles as soil pollutants - Offers comprehensive coverage of soil pollution including types and causes
Publisher: Academic Press
ISBN: 0128498722
Category : Science
Languages : en
Pages : 314
Book Description
Soil Pollution: From Monitoring to Remediation provides comprehensive information on soil pollution, including causes, distribution, transport, the transformation and fate of pollutants in soil, and metabolite accumulation. The book covers organic, inorganic and nanoparticle pollutants and methodologies for their monitoring. Features a critical discussion on ecotoxicological and human effects of soil pollution, and strategies for soil protection and remediation. Meticulously organized, this is an ideal resource for students, researchers and professionals, providing up-to-date foundational content for those already familiar with the field. Chapters are highly accessible, offering an authoritative introduction for non-specialists and undergraduate students alike. - Highlights the relevance of soil pollution for a sustainable environment in chapters written by interdisciplinary expert academics and professionals from around the world - Includes cases studies of techniques used to monitor soil pollution - Includes a chapter on nanoparticles as soil pollutants - Offers comprehensive coverage of soil pollution including types and causes
Air Pollution Episodes
Author: Peter Brimblecombe
Publisher: World Scientific
ISBN: 1786343428
Category : Technology & Engineering
Languages : en
Pages : 397
Book Description
Episodes of air pollution throughout the 20th and 21st centuries have had a huge influence socially, economically and politically. From the Great Smog of London to the Kuwait Oil Fires, and from the ashes of Mount St Helens to air pollution in Beijing, this book chronicles their enduring legacies in medicine, science and public policy. Using technical information and insight from witnesses directly involved in the incidents, ten key episodes are brought together to allow comparison and analysis.Written for students, academics and professionals of atmospheric physics and chemistry, environmental science, public policy and other clinical disciplines, Air Pollution Episodes provides the unique opportunity to understand and learn from the most famous and sometimes devastating incidences of air pollution globally.
Publisher: World Scientific
ISBN: 1786343428
Category : Technology & Engineering
Languages : en
Pages : 397
Book Description
Episodes of air pollution throughout the 20th and 21st centuries have had a huge influence socially, economically and politically. From the Great Smog of London to the Kuwait Oil Fires, and from the ashes of Mount St Helens to air pollution in Beijing, this book chronicles their enduring legacies in medicine, science and public policy. Using technical information and insight from witnesses directly involved in the incidents, ten key episodes are brought together to allow comparison and analysis.Written for students, academics and professionals of atmospheric physics and chemistry, environmental science, public policy and other clinical disciplines, Air Pollution Episodes provides the unique opportunity to understand and learn from the most famous and sometimes devastating incidences of air pollution globally.
Bioremediation Science
Author: Amitava Rakshit
Publisher: CRC Press
ISBN: 1000280705
Category : Technology & Engineering
Languages : en
Pages : 519
Book Description
This book provides state of the art description of various approaches, techniques and some basic fundamentals of bioremediation to manage a variety of organic and inorganic wastes and pollutants present in our environment. A comprehensive overview of recent advances and new development in the field of bioremediation research are provided within relevant theoretical framework to improve our understanding for the cleaning up of polluted water and contaminated land. The book is easy to read and language can be readily comprehended by aspiring newcomer, students, researchers and anyone else interested in this field. Renowned scientists around the world working on the above topics have contributed chapters. In this edited book, we have addressed the scope of the inexpensive and energy neutral bioremediation technologies. The scope of the book extends to environmental/agricultural scientists, students, consultants, site owners, industrial stakeholders, regulators and policy makers.
Publisher: CRC Press
ISBN: 1000280705
Category : Technology & Engineering
Languages : en
Pages : 519
Book Description
This book provides state of the art description of various approaches, techniques and some basic fundamentals of bioremediation to manage a variety of organic and inorganic wastes and pollutants present in our environment. A comprehensive overview of recent advances and new development in the field of bioremediation research are provided within relevant theoretical framework to improve our understanding for the cleaning up of polluted water and contaminated land. The book is easy to read and language can be readily comprehended by aspiring newcomer, students, researchers and anyone else interested in this field. Renowned scientists around the world working on the above topics have contributed chapters. In this edited book, we have addressed the scope of the inexpensive and energy neutral bioremediation technologies. The scope of the book extends to environmental/agricultural scientists, students, consultants, site owners, industrial stakeholders, regulators and policy makers.