Exposure Science Protecting Us from Chemical Physical and

Exposure Science: Protecting Us from Chemical, Physical, and Biological Agents www. isesweb. org

Organization of Presentation • Description of Exposure Science • Exposure Science: Why does it Matter? • Examples of the Impacts of Exposure Science • Realizing the Promise of Exposure Science for the 21 st Century 2

What Is Exposure Science? • The bridge between the sources of chemical, physical and biological agents and human health – Provides crucial information to estimate reallife risks to health and to identify the most effective ways to prevent and reduce these risks. 3

Human Health Risk Assessment and Management 4

Exposure Science: Why Does it Matter? • Exposure information is crucial to protecting health • Exposure science is required to put hazard data into perspective • Predictive exposure science is fundamental to identifying emerging trends and preventing and reducing public health risks from environmental agents in the upcoming decades • Supporting exposure science now will pay 5

Examples of the Impacts of Exposure Science • • Protecting ecosystems Protecting people from physical agents Protecting people from infectious agents Protecting people from chemical agents http: //www. nature. com/jes/webfocus/esdigests/index. html 6

Oil Spills and Fish Health: Exposing the Heart of the Matter • Marine ecosystems fundamental to life, from single-cell organisms to humans, and to world economies • These ecosystems have great resilience, but retain significant vulnerability to disturbances • Major oil spills get major public, but limited scientific, attention • Multiple small oil spills occur almost daily with virtually no attention – Stormwater runoff from streets, atmospheric “fall out” from motor vehicle emissions, spills of “bunker” fuel which powers large ships, etc. – Such spills will increase with rising automobile ownership, coastal population growth, and expansion of container 2011 Incardona et al. , JESEE 21: 3, shipping • Result: limited ability to predict effects of major spills and 7

Oil Spills and Fish Health: Exposing the Heart of the Matter (2) • Most people familiar with the immediate tragedy of oil-soaked birds and marine mammals after major spills • We now know that our conventional wisdom is too limited, and many less visible impacts can occur (e. g. , effects on hearts of fish embryos) • Exposure science, coupled with toxicology, can lead the way in protecting and Head Region of Hatching-Stage Fish Embryos. Heart (Indicated by Arrows) shows adverse fluid accumulation after exposure. Incardona et al. , JESEE 21: 3, 2011 8

Better Radiation Exposure Estimation for the Japanese Atomic-Bomb Survivors Enables Us to Better Protect People from Radiation Today • Medical exposure of US population to ionizing radiation higher now (half of total in chart at right) • Acute effects of high doses recognized early • Chronic effects of lower doses now known to include cancer and non-cancer diseases • Knowledge of doseresponse crucial to Sources of Radiation Exposure to the US Population Cullings & Smith, JESEE 20: 575, 2010 9

Better Radiation Exposure Estimation for the Japanese Atomic-Bomb Survivors Enables Us to Better Protect People from Radiation Today (2) • Ongoing innovations in exposure assessments of Japanese atomic-bomb survivors continue to improve understanding of radiation health effects • These survivors are still teaching us about doseresponse effects, enabling scientists to identify harmful doses • Helps to decide when protective actions are necessary, including – Workers at risk use protective equipment or limit time in radiation areas – Radon measurements required for sale of houses in several states – Newer generation of medical “x-ray” machines and Cullings & patients techniques delivers lower doses to. Smith, JESEE 20: 575, 2010 10

Anthrax: Modern Exposure Science Combats a Deadly Ancient Disease • Inhalation anthrax mortality higher than 90% if untreated and often deadly, even with antibiotic therapy and supportive care • Course of infection has “point-of-no-return” after which all traditional treatments may fail • Exposure science can Colored Scanning Electron Micrograph of Anthrax Bacteria (Bacillus anthracis) Barr et al. , JESEE 20: 573, 2010 11

Anthrax: Modern Exposure Science Combats a Deadly Ancient Disease (2) • Exposure science advancements – Earlier diagnosis, even before symptoms, so treatment can begin sooner – Analyzes many more blood samples/day so useful to blunt epidemics or impacts of terrorist attacks – Can track infection even if antibiotic treatment started so easier to prevent more infections – Quantifies course of infection so “point-of-no-return” can be avoided – Quantifies efficacy of treatments so interventions work better Barr et al. , JESEE 20: 573, 2010 12

Exposure Science for Viral Diseases: 2009 H 1 N 1 Pandemic Influenza Virus • Influenza virus has a history of killing millions of people • In 2009, World Health Organization declared pandemic of 2009 H 1 N 1 viruses – 57 million people worldwide infected – 22 million people in US infected and over 14, 000 died Scanning Electron Micrograph of H 1 N 1 Influenza Virus Cox et al. , JESEE 21: 1, 2011 13

Exposure Science for Viral Diseases: 2009 H 1 N 1 Pandemic Influenza Virus (2) • Exposure science taught us how to prevent transmission of influenza with simple measures (e. g. , properly washing hands, coughing into one’s sleeve) • More current exposure science enables earlier detection and identification of novel viruses, leading to – Development of more effective seasonal vaccines (vaccines now are developed a year ahead of the flu season so prediction very important) – Shortening of time for development of seasonal Cox et al. , JESEE 21: 1, 2011 vaccine 14

Superfund: Is It Safe to go Home? • 1980 Superfund law directs EPA to clean up abandoned hazardous waste sites. • Estimate: 1 in 4 Americans lives within 4 miles of Superfund site; approx. 10 million under 12 years old Lioy & Burke. JESEE 20: 113, 2010 15

Superfund: Is It Safe to go Home? (2) • Superfund law does not effectively address exposure of residents near sites • Conversely, exposure science results are essential to – Prioritize listed sites based upon those that pose the highest risks – Develop effective cleanup plan (e. g. , water, air, house dust? )that prevents future exposures – Determine whether the clean up actually has reduced the potential exposures and risks sufficiently to go home safely Lioy & Burke. JESEE 20: 113, 2010 • Exposure science results can be used to 16

Out of the Frying Pan and Out of the Fire • Many laws and consumer demands lead to reduction or ban of chemicals, but their function is still needed • Which is riskier: the “banned” chemical or the “replacement” chemical? • We often know more about the banned chemical • Exposure science indispensable to avoid unwanted exposures to replacement La. Kind & Birnbaum JESEE 20: 113, 2010 chemicals 17

Out of the Frying Pan and Out of the Fire (2) Dramatic increase in PBDE flame retardants in breast milk of Swedish women Nanograms PBDE per gram milk fat • Flame retardants reduce fire incidence and severity • One class of retardants (PBDE) was a replacement chemical in the 1970’s and widely used until unexpected exposure occurred, resulting in bans and voluntary phaseouts • Exposure to replacements for PBDEs now occurring • Need exposure science to be proactive when evaluating replacements to avoid unexpected exposures La. Kind & Birnbaum JESEE 20: 113, 2010 18

Protecting Children from Pesticides and Other Toxic Chemicals • Exposure science breakthrough in 1990’s: recognition by policy makers of unique exposures and vulnerabilities of fetuses, infants, and children to many chemicals • Result: new laws and policies (e. g. , Food Quality Protection Act focuses on protecting Boys Bathing in Recycled Pesticide Drum Landrigan & Goldman, JESEE, 21: 117, 2011 19

Protecting Children from Pesticides and Other Toxic Chemicals (2) • Pesticides in the Diets of Infants and Children (NRC, 1993) – Children have greater exposures than adults on body weight basis (e. g. , 1 -yr old drinks 21 times more apple juice) – Children’s metabolic pathways immature (e. g. , can’t detoxify as much of some chemicals) – Children have rapid growth and development, resulting in windows of vulnerability (e. g. , brain injury from methylmercury) – Children have more 2011 Landrigan & Goldman, JESEE, 21: 117, time to develop chronic diseases related to harmful exposures (e. g. , early exposure can 20

Protecting Children from Environmental Risks Throughout Each Stage of their Childhood • Children breath, eat, and drink proportionally more than adults, especially early in life • Age-related differences in behavior (e. g. hand-tomouth activity) impact exposure • Toxicological sensitivity varies by age (from conception up) – thus, important to identify and account for “windows of susceptibility” • Firestone EPA incorporating U. S. JESEE 20: 227, 2010 lifestage susceptibility into Total water ingestion (all sources), 95 th percentile 21

Protecting Children from Environmental Risks Throughout Each Stage of their Childhood (2) • U. S. EPA created standard set of 10 post-birth childhood age groups to account for lifestage differences when assessing and monitoring exposure to environmental toxicants • U. S. EPA also has developed a complementary set of post-birth childhood age groups based on toxicological sensitivity to carcinogens which act via mutagenicity • Already impacting risk assessments Firestone JESEE 20: 227, 2010 22

Ensuring the Safety of Chemicals Turn wishes into reality: Begin a new era of chemical management, with crucial support from exposure science: • Modernize US Toxic Substance Control Act (TSCA) that regulates potentially toxic chemicals, by having more exposure and effects information • Modify chemicals by design to be less toxic and less persistent in environment “Wish I could always keep their environment safe!” Anastas et al. , JESEE 20: 395, 2010 23

Ensuring the Safety of Chemicals (2) • Over 10, 000 chemicals currently in use, with more being added each day – Older chemical-by-chemical approach to safety inadequate – Need sustainable approach to achieve safety while reaping benefits of chemicals • Exposure science fundamental to – Manage risks by creative design – Holistic understanding of use to prevent unintended consequences – Predict risk before it occurs – Empower people to make educated personal Anastas et al. , JESEE 20: 395, 2010 decisions 24

MTBE: a Poster Child for Exposure Assessment as Central to Effective TSCA Reform • U. S. Toxic Substances Control Act (TSCA) being revised by Congress to be more health-protective • Advanced assessment of all major exposure pathways vital to improving TSCA • Recent history of MTBE (an oxygenated fuel additive intended to reduce exposures to carbon monoxide and ozone) Goldstein, JESEE 20: 229, 2010 demonstrates need for exposure science 25

MTBE: a Poster Child for Exposure Assessment as Central to Effective TSCA Reform (2) • MTBE legally required based on very poorly founded assumptions about health benefits • 100 million Americans exposed before adequate knowledge of exposure and heath effects available • MTBE leaked from tanks, contaminating drinking water, with economic & potential health impacts • Problems could have been Leaking Underground Fuel Storage Tank Goldstein, JESEE 20: 229, 2010 26

Targeting the Components Most Responsible for Airborne Particulate Matter Health Risks • Airborne particulate matter (PM) causes morbidity and mortality • U. S. EPA sets healthprotective Nat’l Ambient Air Quality Standards (NAAQS) for PM by mass, with aerodynamic diameter cut points of 10µm and 2. 5µm, based on both different chemical components and regional lung deposition Lippmann JESEE 20: 117, 2010 • Exposure science crucial Regional Respiratory Tract Deposition of Particles 27

Targeting the Components Most Responsible for Airborne Particulate Matter Health Risks (2) • Exposure science shows coarse thoracic PM (› 2. 5; ‹ 10µm) chemistry and sources different from fine PM (‹ 2. 5µm) • Toxicity also differs as a result of sites of deposition • Next generation of PM NAAQS needs to better account for toxic components, not just mass by size • Lippmann JESEE 20: 117, 2010 exposure science Application of fundamental to the adoption of more 28

The Smoking Gun: Working to Eliminate Tobacco Smoke Exposure • Science indicates there is no risk-free level of exposure to second-hand smoke (SHS) (US DHHS, 2006, Surgeon General Rpt) • Exposure science basic to develop and implement smokefree legislation around the world (e. g. , graphic) Breysse & Navas-Acien, JESEE 20: 397, 2010 29

The Smoking Gun: Working to Eliminate Tobacco Smoke Exposure (2) • Exposure science shows: – Locations (e. g. , restaurants, bars, casinos) with elevated SHS levels, providing guidance for behavior and laws – Mechanical ventilation systems and separate nonsmoking sections in public places are insufficient to protect non-smokers – Personal exposures of the general populace and specific groups, driving policies/laws and allowing JESEE 20: 397, 2010 Breysse & Navas-Acien, evaluation of efficacy of or compliance with exposure reduction actions 30

Exposure Science Can Increase Protection of Workers and their Families from Exposure to Asbestos and Inform on the Effects of Other Elongate Mineral Particles • Inhaled asbestos fibers can cause serious Asbestos Bodies in a Human Lung diseases (e. g. , mesothelioma, lung cancer, asbestosis) • In the mid 1900’s, not understanding and acting upon exposures early enough to intervene led to mortality of workers and Bar= 20µm diseases in their families • Exposure science enables Howard & Middendorf, JESEE 20: 487, 2010 us to avoid repeating this history 31

Exposure Science Can Increase Protection of Workers and their Families from Exposure to Asbestos and Inform on the Effects of Other Elongate Mineral Particles (2) • Impacts of prior exposures continues – 77 asbestosis deaths in 1968 and 1, 493 in 2000 • Exposure science warned of – Secondhand exposure of family contacts of asbestos workers – Public risks of exposures during asbestos removal efforts • Exposure science needed to understand risks from modern-day types of occupational exposures • New concerns over “elongate mineral particles” that share some asbestos properties – Present an opportunity to use exposure science to Howard & Middendorf, JESEE 20: 487, 2010 avoid the mistakes of the past with asbestos 32

Getting the Lead Out: Important Exposure Science Contributions • Lead has adverse health effects at all ages for most organ systems, but greatest concern over developing nervous system of fetuses, infants, and young children • This led to several successful national and international regulatory actions to reduce lead exposure based on exposure science, especially knowledge of – Exposure pathways and sources – Computer modeling of relationships between external Grant, exposures and internal lead burdens JESEE 20: 577, 2010 33

Getting the Lead Out: Important Exposure Science Contributions (2) • Dramatic decrease in children’s blood lead initially due to phase- out of leaded gasoline in U. S. • Later decreases due to acting on knowledge of pathways of exposure from other sources Percentage of children 1 -5 years old in the U. S. population with elevated blood lead levels (leaded house paint, house dust, drinking water from leaded plumbing, food, etc. ) • As “safe” levels of lead decrease, continued vigilance using exposure science needed for continued reductions from additional and Grant, JESEE 20: 577, 2010 34

Vehicle Emissions: Progress and Challenges U. S. Highway Vehicle Fleet Emissions Reductions since 1970 0 -10 PERCENT CHANGE FROM 1970 • Dramatic decreases (99% since 1970) in emissions counterbalanced by dramatic increase (170% since 1970) in vehicle miles traveled (VMT) • Emissions major regulatory target to reduce ambient air health risks by reducing exposures • But, understanding exposures to emissions Sawyer, (emissions, very complex. JESEE 20: 489, 2010 VMT, air fate & -20 -30 -40 -50 NOx PM 2. 5 CO VOC -60 -70 -80 -90 1975 1980 1985 1990 YEAR 1995 2000 2005 35

Vehicle Emissions: Progress and Challenges (2) • Major challenges remain – Electric-drive (incl. hybrids) will help, but not a lot – “High-emitters” among the fleet – Heavy-duty vehicles have slower turnover and less emissions regulations – As on-road emissions decrease, proportion of non-road mobile sources increasing • Ozone and particulate matter (<2. 5µm) still health concerns • Must know more about quantitative relationship of vehicle emissions to actual exposure (by mass, Sawyer, JESEE 20: 489, 2010 number, chemistry & size) so regulations more 36

REALIZING THE PROMISE OF EXPOSURE SCIENCE FOR THE 21 ST CENTURY REQUIRES INNOVATION AND TRANSFORMATION OF EXPOSURE SCIENCE Hubal et al. , JESEE 21: 119, 2011 37

The Promise of Exposure Science • Exposure science is a bedrock for protection of public health • It fundamentally informs decisions for – Smart and sustainable design – Prevention and mitigation of adverse exposures – Health protection Hubal et al. , JESEE 21: 119, 2011 38

Future Challenges for Exposure Science • Sustainability: Improve the health of individuals and communities today without compromising the health and welfare of future generations • Risk analysis: Incorporate exposure science more effectively and efficiently into decisions • Prevention: Shift from treatment to prevention of Hubal et al. , JESEE 21: 119, 2011 diseases through improved understanding of the role of environmental 39

Realizing the Promise Requires a Fundamental Cultural Shift Towards: • Trans-disciplinary collaborations that provide linkages between exposure and health sciences • A suite of innovative scientifically based tools and approaches to support public health decisions • Holistic approaches to policy making • Commitment of resources to trans. Hubal et al. , JESEE 21: 119, 2011 disciplinary long-term research and training 40

MORE INFORMATION • The Digests which formed the foundation for this presentation are available for free download at: – http: //www. nature. com/jes/webfocus/esdigests /index. html • Please visit www. isesweb. org for more information. 41

SCIENCE FOR BETTER ENVIRONMENTAL HEALTH This presentation and all articles cited from Journal of Exposure Science and Environmental Epidemiology (JESEE) are available for free at www. isesweb. org; for articles click on Exposure Digests