Clarke Lecture: How Safe Is Safe in the Treatment of Drinking Water for the Public? - Dr. Trussell

Summary

El guion del video ofrece una perspectiva histórica y actual sobre la seguridad del agua potable, desde la conexión entre agua contaminada y enfermedades en el siglo XIX hasta los desafíos de las sustancias químicas y orgánicas trazas en la era moderna. Se discuten avances en tratamientos de agua, la importancia de la regulación y la necesidad de un nuevo paradigma para abordar los riesgos emergentes, enfatizando la importancia de la ciencia y la colaboración para garantizar el agua potable seguro.

Takeaways

• 😐 La relación entre el agua potable y las enfermedades se estableció en 1854 por John Snow, quien demostró que un brote de cólera en Londres estaba vinculado al agua de un pozo específico.
• 🔬 Durante el siglo XIX y gran parte del siglo XX, el enfoque en el agua potable se centró en el tratamiento para prevenir enfermedades transmitidas por el agua, como la caries y la fiebre tifoidea.
• 🏭 El desarrollo de la industria química en el siglo XX trajo consigo avances significativos pero también problemas, como la creación de compuestos químicos que persisten en el medio ambiente y en el agua potable.
• 🌐 La publicación de 'Cierto silencio' por Rachel Carson en 1962 marcó un punto de inflexión en la discusión nacional sobre los impactos negativos de ciertos compuestos químicos, especialmente el DDT.
• 🔬 A finales de los 1960, las técnicas analíticas mejoraron significativamente, permitiendo la detección de contaminantes químicos en el agua, incluyendo los productos químicos porosos (BTEX) y los compuestos orgánicos volátiles (VOC).
• 🚰 A lo largo del siglo XX, se implementaron cambios en el tratamiento del agua para prevenir los productos químicos secundarios y se establecieron programas para limpiar las aguas subterráneas contaminadas.
• 📉 La regulación del agua potable se vio influenciada por la Ley de Delany, que buscaba erradicar cualquier cantidad de carcinógenos en los alimentos, lo que llevó a la EPA a establecer límites de calidad del agua (MCL) basados en límites de cuantificación prácticas.
• 🌿 La detección de nuevos grupos de compuestos químicos en las aguas, incluyendo medicamentos, productos de cuidado personal y hormonas, ha elevado preocupaciones sobre la seguridad del agua potable.
• 📉 La tecnología de análisis del agua ha avanzado rápidamente, lo que permite detectar trazas de compuestos químicos a niveles cada vez más bajos, planteando desafíos para determinar cuándo el agua es considerada segura.
• ⚖️ Se sugiere que se necesite una nueva discusión sobre el riesgo y la seguridad del agua potable, considerando la detección de compuestos químicos a niveles cada vez más bajos y la necesidad de un enfoque precautorio.
• 🛡️ Se propusieron cuatro directrices para abordar la nueva era de contaminantes en el agua, incluyendo la preferencia por no tener compuestos químicos人造 en el ambiente, el reconocimiento de que este principio no siempre es factible, la búsqueda de mejoras continuas en el tratamiento del agua y la búsqueda de sustitutos para compuestos persistentes.

Q & A

¿Cuál es la conexión entre el agua potable y las enfermedades?

La conexión entre el agua potable y las enfermedades se estableció en 1854 por John Snow, quien demostró que un brote de cólera en Londres estaba conectado con el agua tomado de un pozo específico.

¿Qué cambios se produjeron en el tratamiento del agua potable durante el siglo XIX y principios del siglo XX?

Durante el siglo XIX y principios del siglo XX, el enfoque fue en el tratamiento del agua para prevenir enfermedades transmitidas por el agua, como la fiebre tifoidea y el cólera, mediante la presión continua, la filtración rápida y la clorazione.

¿Qué símbolo se asoció con el agua potable segura en el siglo XX?

En el siglo XX, el olor a cloro en el agua potable se convirtió en un símbolo de que el agua estaba libre de enfermedades microbianas, representando que una civilización había entrado en la Edad Moderna.

¿Cuál fue el impacto de la industria química en el agua potable?

El desarrollo de la industria química en el siglo XX llevó a la creación de muchos compuestos que mejoraron la vida cotidiana, pero también introdujo sustancias químicas en el agua, lo que generó preocupaciones sobre la seguridad del agua potable.

¿Qué fue el punto de inflexión en la discusión nacional sobre los efectos de los pesticidas y otros compuestos químicos?

El punto de inflexión fue en 1962 con la publicación del libro 'Silent Spring' de Rachel Carson, que demostró las consecuencias no anticipadas de ciertos compuestos químicos, en particular el DDT.

¿Cómo se detectaron por primera vez los contaminantes orgánicos en el agua potable?

Los contaminantes orgánicos en el agua potable se detectaron por primera vez en la década de 1960 gracias a las mejoras en las técnicas analíticas, especialmente el Cromatografo de gases y el Espectrómetro de masas.

¿Qué son los compuestos disinfección por desinfección (DBP) y por qué son importantes?

Los compuestos disinfección por desinfección (DBP) son sustancias químicas que se forman cuando se utiliza cloro para desinfectar el agua, y son importantes porque pueden representar un riesgo para la salud, a pesar de que se encuentren en niveles muy bajos.

¿Cuál es la relación entre la regulación del agua potable y la 'Ley de la dosis práctica' (PQL)?

La 'Ley de la dosis práctica' (PQL) es el nivel más bajo que se puede medir de forma confiable, y ha sido utilizado para establecer el nivel máximo contable (MCL) para los carcinógenos en el agua potable, con el objetivo de ser lo más cercano a cero que sea factible.

¿Qué son los compuestos orgánicos emergentes y cómo afectan el agua potable?

Los compuestos orgánicos emergentes son una nueva clase de sustancias químicas, incluyendo medicamentos, productos de cuidado personal, y hormonas, que se encuentran en niveles muy bajos en el agua potable y que representan un desafío para su tratamiento y regulación.

¿Qué sugiere el discurso para abordar los riesgos asociados con los compuestos orgánicos en el agua potable?

El discurso sugiere la necesidad de un nuevo enfoque para determinar qué niveles de compuestos orgánicos son aceptables en el agua potable, lo que podría incluir la adopción de un enfoque de precaución, la mejora continua en el tratamiento del agua, y la búsqueda de sustitutos para compuestos persistentes.

Outlines

00:00

🧪 La Seguridad del Agua Potable a lo largo del Tiempo

El primer párrafo aborda la perspectiva histórica y tecnológica de la seguridad del agua potable, desde la conexión establecida en 1854 entre el agua potable y las enfermedades, hasta los avances en tratamiento del agua en el siglo XX. Se mencionan figuras clave como Tom Hawkley, George Fuller, John Leal y la lucha contra enfermedades transmitidas por el agua. La introducción del cloro como desinfectante y la reducción en tasas de mortalidad son destacadas como logros significativos, con el olor al cloro considerado un símbolo de agua segura y un paso hacia la Edad Moderna.

05:00

🚗 El Desarrollo de la Industria Química y sus Consecuencias

El segundo párrafo explora el desarrollo de la industria química en el siglo XX y su impacto en la vida cotidiana, desde el caucho sintético hasta el DDT y otros compuestos químicos. Sin embargo, también se destaca el cambio en la percepción pública hacia estos compuestos químicos, especialmente después de la publicación de 'Silent Spring' por Rachel Carson en 1962, que resaltó los efectos no intencionados de ciertos compuestos, como el DDT, en el medio ambiente. La aparición de contaminantes en el agua, incluyendo los byproducts químicos causados por el cloro, y la respuesta de la EPA y la sociedad a estos hallazgos se discuten.

10:02

🔬 Avances en la Tecnología de Análisis de Agua y Nuevos Desafíos

El tercer párrafo narra el progreso en la tecnología de análisis de agua, especialmente la introducción del gas chromatograph mass spectrometer, y cómo esto ha permitido la detección de contaminantes químicos en niveles cada vez más bajos. Se mencionan los desafíos que representan los nuevos compuestos orgánicos trazables (POCIs) y los compuestos orgánicos volátiles (VOCs), y cómo la ciencia y la regulación han tratado de abordar estos problemas. También se discute la evolución de las políticas de regulación del agua, incluyendo el concepto de nivel máximo de contaminación (MCL) y el límite de quantificación práctico (PQL).

15:04

🌐 La Nueva Era de Contaminantes Orgánicos y el Desafío de la Seguridad del Agua

El cuarto párrafo enfatiza la llegada de una nueva era caracterizada por la rápida expansión de la población mundial y el comercio, y cómo esto está impactando el medio ambiente y la presencia de contaminantes orgánicos en el agua. Se discuten los desafíos de evaluar y manejar estos contaminantes en ausencia de una comprensión científica completa de sus efectos, y se sugieren posibles enfoques para abordar estos problemas, como la mejora continua en el tratamiento del agua y la búsqueda de alternativas a compuestos persistentes.

20:06

🛡️ La Búsqueda de un Nuevo Paradigma para la Seguridad del Agua

El quinto párrafo aborda la necesidad de un nuevo paradigma para definir la seguridad del agua en la era de los contaminantes orgánicos trazables. Se sugieren cuatro directrices para abordar esta nueva realidad, incluyendo la preferencia por el agua libre de compuestos antropogénicos, la necesidad de un filtro para tomar decisiones antes de que la ciencia esté disponible, la mejora continua en el tratamiento del agua y la búsqueda de sustitutos para compuestos persistentes. Se discute la importancia de un enfoque precautorio y la utilización de criterios de riesgo mínimo para guiar inversiones y regulaciones.

25:08

🤒 Los Contaminantes Microbiológicos y su Relevancia en la Seguridad del Agua

El sexto párrafo compara los riesgos de los contaminantes orgánicos trazables con los de los contaminantes microbiológicos, destacando que, a pesar de la baja concentración de los primeros, los segundos, aunque en concentraciones más bajas, pueden tener consecuencias más inmediatas y graves para la salud humana. Se argumenta que, aunque los avances en la detección y tratamiento de contaminantes químicos son importantes, los patógenos siguen siendo una amenaza significativa para la seguridad del agua y merecen una inversión continua en la ciencia y el control.

🏆 Agradecimientos y Reconocimiento de la Trayectoria del Orador

El último párrafo no es parte del discurso principal, sino que es un agradecimiento del moderador por la presentación y un reconocimiento a los premios y a las personas involucradas en el evento, incluyendo a los receptores previos del Premio Clark, a la familia y amigos del orador, y a los patrocinadores y voluntarios que hicieron posible la celebración.

Keywords

💡Tratamiento del agua potable

El tratamiento del agua potable se refiere al proceso de purificación y desinfección del agua para su consumo humano. En el guion, se menciona que desde el siglo XIX se centró en el tratamiento del agua para prevenir enfermedades transmitidas por el agua, como la cólera y la fiebre tifoidea, lo que demuestra la importancia histórica y continua de este concepto en la seguridad del agua potable.

💡Desinfección

La desinfección es un método utilizado para eliminar o reducir el número de microorganismos en el agua. En el guion, se destaca la introducción de la clorazione como un método de desinfección en Estados Unidos, lo que contribuyó significativamente a la reducción de las tasas de mortalidad por enfermedades relacionadas con el agua.

💡Industria química

La industria química es un sector que se enorgullece de sus avances en la producción de compuestos que mejoran la vida cotidiana. Sin embargo, el guion señala que los avances de la industria química en el siglo XX también trajeron problemas, como la contaminación del agua potable con productos químicos que no se anticiparon inicialmente.

💡Plomo de cloro

El plomo de cloro es un compuesto químico que se forma como subproducto al tratar el agua con cloro. Aunque el cloro es eficaz para la desinfección, el guion menciona que también puede generar compuestos orgánicos por desecho, como el plomo de cloro, lo que plantea un desafío para la calidad del agua potable.

💡Rachel Carson

Rachel Carson fue una bióloga y escritora conocida por su libro 'Silent Spring', que alertó sobre los efectos negativos de ciertos pesticidas en el medio ambiente. En el guion, se la menciona como un punto de inflexión en la conversación nacional sobre los problemas ambientales, incluidos los relacionados con el tratamiento del agua.

💡Cromatografía de gases y espectrometría de masas

La cromatografía de gases y la espectrometría de masas son técnicas analíticas que permiten la detección de compuestos químicos en muestras de agua. Estas tecnologías, como se menciona en el guion, mejoraron significativamente en el siglo XX, permitiendo la detección de compuestos orgánicos en el agua que antes no se podían detectar.

💡Compuestos orgánicos por desecho

Los compuestos orgánicos por desecho son productos químicos no deseados que se liberan en el medio ambiente. El guion habla sobre la presencia de estos compuestos en el agua, como resultado de la contaminación causada por la industria química y la agricultura, lo que ha complicado el mantenimiento de la seguridad del agua potable.

💡Regulaciones del agua potable

Las regulaciones del agua potable son leyes y directrices que establecen estándares para la calidad del agua que se sirve al público. El guion menciona cómo las regulaciones han evolucionado para abordar la presencia de compuestos químicos y microbiológicos en el agua, reflejando la complejidad de garantizar la seguridad del agua potable.

💡Riesgo

El riesgo en el contexto del guion se refiere a la posibilidad de daño o perjuicio, especialmente en relación con la salud pública y el medio ambiente. Se discute cómo se evalúa y gestiona el riesgo asociado con las sustancias en el agua, y cómo la percepción pública y las políticas pueden influir en la regulación y el tratamiento del agua.

💡Precaución

La precaución es un principio que se menciona en el guion como una posible estrategia para manejar la incertidumbre en la ciencia y la regulación del agua potable. Se sugiere que, en lugar de esperar una prueba definitiva de daño, se deben tomar medidas preventivas cuando se identifican riesgos potenciales, lo que puede ser controvertido pero también esencial para la protección de la salud pública.

Highlights

No man does his work alone, emphasizing the importance of collaboration in achieving success.

The connection between drinking water and disease was established in 1854 by John Snow using maps and interviews.

19th and 20th centuries' focus on water treatment to prevent waterborne diseases like cholera and typhoid fever.

Introduction of key figures in water treatment advancements: Tom Hawkley, George Fuller, John Le, and the role of chlorine.

The rapid decline in death rates due to effective water treatment in the US during the first half of the 20th century.

The Modern Age brought challenges such as the development of the chemical industry and its impact on safe drinking water.

Rachel Carson's 'Silent Spring' highlighted the significant consequences of chemicals like DDT, changing the national dialogue.

The discovery of disinfection byproducts like chloroform and the presence of VOCs in groundwater.

The challenge of determining safe levels of trace organic chemicals in drinking water with limited evidence of health risks.

The implementation of the Superfund program to clean up groundwater and the shift in disinfection methods.

The development of analytical techniques like gas chromatograph mass spectrometer for detecting trace chemicals in water.

The presence of residual drugs, personal care products, and hormones in waterways as a new concern for water safety.

The rapid expansion of detection capabilities for trace organics, suggesting a 'new law' similar to Moore's law for technology.

The need for a new paradigm for safe water due to the impact of population growth and commerce on the environment.

The proposal of four guidelines for managing trace organic chemicals in water, including seeking continuous improvement.

The importance of finding substitutes for manmade compounds that persist in the environment and prioritizing those with health effects.

The comparison between the risks of trace organic compounds and microbiological contaminants in drinking water.

The call for investment in understanding pathogens and their control in water, especially considering potential water reuse.

The summary emphasizing that while trace organic chemicals capture our attention, pathogens remain the most significant health risk in water.

Transcripts

no man does his work alone and I wrote a

little insert that you all have that you

can read at your leisure that talks

about some people that I collaborated

with while I done my work so I won't go

through that any any further here I'll

just if you don't mind I'll just jump

into my my

presentation so so in this talk I'll try

to provide a a long-term perspective on

the issues we face in making water safe

making drinking water safe I'll take us

back in the past to the middle of the

19th century David already did some of

that we'll talk about what happened

since then and then we'll talk about the

New Age The Next Generation must face

the title of the talk is how safe is

safe in the treatment of drinking

water so the connection between drinking

water and disease was established in

1854 by John Snow a noted physician in

Victorian England using maps and

interviews of the effective population

snow connected the collar outbreak in

London at the time through drinking

water taken from the Broad Street

well during 19th century and much of the

20th century that followed the focus in

drinking water then was on the treatment

of water to prevent waterborne disease

diseases like chera in typhoid fever

showing the little organisms that that

we all love that are responsible for

that here are some early Personalities

in that effort I've just picked a few

among many Tom hawkley a civil engineer

in Victorian England who is an advocate

of continuous pressurization of Water

Systems to prevent

contamination George Fuller who

developed rapid Sand Filtration to

purify the water John le the first to

introduce chlorination in the United

States to disinfect the water and able

woman who played a pivotal role in the

adoption of chlorination Nationwide as

as we mentioned

earlier data on the rapid decline of

death rates in the US in the first half

of the 20th century like this CDC data

shown here are often cited to

demonstrate that drinking water

treatment was one of the greatest

engineering achievements of the 20th

century by the 1960 when I graduated

from high school it might even be said

that our Public Health officials took

comfort in just a little bit of a

chlorine smell in the drinking water it

was a sign that their water was free

from microbial

disease that chlorine smell was a happy

moment in fact you could say Safe

Drinking Water became a symbol that a

civilization had made it into the Modern

Age but the Modern Age also brought

other problems with

it safe drinking water was only one of

the great achievements of Science and

Engineering in 20th century another

great achievement was the development of

our chemical industry we invented a lot

of chemicals to make our life easier

Dupont even coined the slogan Better

Living Through Chemistry let me give you

some examples of the important chemicals

that were invented in the first half of

the 20th

century when when rubber was in short

supply we invented synthetic rubber we

still make our tires with it

today I don't have to tell you how

important penan is it was discovered in

1928 but making large quantities was a

very difficult thing to achieve but by

1944 uh in the middle of World War II we

were making millions of doses for our

troops we invented nylon as since

synthetic fiber that replaced silk in

women's stockings Nyon is both tougher

and cheaper than silk I remember when I

was a kid my mother you know nylons were

cheaper than silk stockings but you can

only wear a Silk Stocking once because

they were ruined after

that and nowadays I don't think anybody

wears

some

DDT the miracle pesticide we use it for

everything for lice pests in the kitchen

elm disease mosquitoes I remember my dad

spraying it all over the

place for me personally one of the most

dramatic was the herbicide

daon dond came out in the mid1 1950s

when I was a kid and one of my chores

was to pull the crab grass out of our

dondra

lawn I spent a lot of long hot

summer afternoons in that lawn I grew up

in Southern

California for me

personally well

so then my uncle Amos who was a farmer

told my dad about

daon my dad sprayed daon on the lawn the

stuff killed the grab grass but it

didn't touch the dondra I was sold on

D

the chemical industry as you might

imagine was quite proud of these

achievements this ad from penwal in

1946 or maybe 47 is a good example the

text in the ad Begins the Great

Expectations held for DDT have been

realized during 1946 exhaustive

scientific Studies have shown that when

properly applied DDT kills a host of

destructive pests and is a benefactor to

all of

humanity

and it was

true with all these new chemicals being

as powerful as they

were and with human nature being such

that it is you won't be surprised that

not everyone saw it the same way

chemicals that can produce such

impressive results were naturally

suspect in 1962 a Tipping Point came in

our national dialogue about these issues

when Rachel Carson wrote the book Silent

Spring in that book she demonstrated

that some of the most miraculous of

these manade chemicals DDT in particular

had significant consequences that had

not been

anticipated Carson's book stood the test

of Science and captured the imagination

of the world

Community it was the analytical sciences

that brought the issue to drinking

water in the late 1960s analytical Tech

techniques vastly improved particularly

important was the gas chromatograph Mass

spectrometer using these instruments and

there's one shown here using these

instruments EPA conducted surveys of the

nation's Water Supplies they have found

evidence of chemical spills which they

were looking for but more important they

also found perhaps more important they

also found that when we use chlorine to

disinfect the water it caused chemical

byproducts like chloroform and later on

vol Al organic chemicals which we call

voc's were also found in groundwater

basins all over the

nation when we found these disaffection

btics of vo's we faced some important

decisions on the one hand these

compounds were found at very little

levels we hadn't found them until we had

these fancy

instruments also and this is important

the evidence that they represented a

health risk

was what I call second order science

there was no direct evidence or

certainly very little direct evidence of

Health consequences from Human exposure

rather there was evidence in studies

from animals exposed to much higher

levels of chemicals and that evidence

had to be extrapolated across one

species to another and across orders of

magnitude of concentration and across

Decades of exposure in order to figure

out what what its impact would be

it' be a long time before this issue was

settled

science also the risks imputed were

generally small when compared to the

risks that the population ordinarily

engages in during everyday life the

decisions we make all the

time there were also concerns on the

other side of the Ledger though even

though there was ambiguity about the

level of risk where the customer is

concerned the drinking water customer

the risk is

involuntary so it becomes a matter of

public trust we're making decisions on

behalf of the

public also there was evidence that the

public was concerned about the

issue and finally some important figures

in the industry began to Advocate that

these chemicals be removed Abel wman who

I mentioned before was the one of the

most visible of these figures Abel was

in the late 80s at the time but believe

me he was still very

persuasive so there was a lot of debate

but in the end the nation spent the rest

of the 20th century changing

disinfection to prevent disinfection

byproducts and implementing super uh

super fund program to clean up our

groundwaters

Nationwide so you might ask in light of

all this fuzzy information about the

risks of the chemicals how do we decide

what levels we would

achieve it's important to understand

these regulations written at a time you

can tell I practiced CU it's all

recorded it's important to understand

these regulations written at the time

when the official I look at Washington

DC was still reflected by the Delany

Amendment which was an FDA regulation

that banned any chemicals any chemical

added to food uh which could induce

cancer in

animals so or man man or animals so so

far

carcinogens any amount was unacceptable

no amount was

acceptable so in the operating this

environment EPA proposed an interesting

strategy they proposed an maximum tment

level

goal and a maxent level the max level

was the enforceable level and for

carcinogens the goal would be zero but

the MCL will be set as close to the goal

as feasible but of course there were a

lot of debates about what level is

feasible so to help this resolve this

issue in the debate EPA offered that an

important consideration determining

what's feasible would be the Practical

quantification limit which would be the

lowest level that you could reliably

measure so the lowest feasible level for

an MCL would then be the

pql so from that time on all carcinogens

the M the MCL has been set at

pql in essence through the artifice of

this practical modification limit we set

a goal of Zero no contamination can be

measurable but as a nation struggle to

address Vault organic chemicals and dvps

as we went on in those decades to deal

with it the science of Water Analysis

continued to advance in 1997 just as we

approached the end of the 20th century

German

scientists uh reported the presence of a

new group of chemicals in um European

rivers and streams and then 2002 the um

us Geological Survey published a

national uh study showing these same

chemicals were widespread in US

waterways as

well some of these chemicals were

residual drugs we take to protect our

health and that we then pass on the

environment and our urine other these

residuals of personal care products like

perfume insect repellant or

sunscreen caffeine and coffee others

were natural hormones like estradiol

or e or synthetic hormones like ethanal

esile which we take for birth control

some are sweeteners we use to sweeten up

our sugar-free soft drinks like um

sucrose or Ace sulfane

K now we had a new thing to worry about

these emerging chemicals occur at the

part P trillion level a thousandfold

lower than the dpps and V's we found

four decades ago again the levels are

low enough it's hard know the best

course of

action as we work to meet this challenge

it's becoming clear that we're resolving

it will require resources more than just

our drinking water industry it may

require that we build a new consensus

about what it means to have safe

water these Trace organic chemicals I

would

argue in our environment are harbingers

of a new age that we're now entering

this new age has two characteristics

that are important to understand the

first is the rapid expansion of the

Earth human population which is having

impacts that um are Beyond those we've

experienced before and the second is

that even more rapid impact or expansion

of worldwide

Commerce as the level of our Commerce

continues to increase along with our

population indeed much faster than the

population increases the detrus of our

civilization uh will become increasingly

present in the environment around us

Trace organic chemicals and drinking

water are only one form this debris

takes we see evidence of in the smog in

Southern California that started to

appear in the late 40s early 50s we saw

evidence of acid rain in the

70s the ozone layer in the 80s and of

course the global warming we talked

about earlier

today but where drinking water is

concerned it is the accumulation of the

trans organic chemicals in water that

has become the big

issue for the moment our strategy

continues to be to treat them below the

levels of detection and we've got some

great Hardware to do

it but the Improvement of SC of the

science of Water Analysis is rapid and

inexorable so we're able to find this

chemical detrius our civilization at

lower and lower levels in increasingly

at places we've never been able to find

them before for since

1970 I would argue analytical technology

has been the fastest growing area of

water

science this chart shows a crude plot of

the history of detection from measuring

ter Organics and water during the course

of my career and well beyond the idea is

we can make our own equivalent of Mo's

law so you know Mor was the guy who said

that the number of transistors on a

microchip doubles every two years well

you know you could say say that our new

law will be the detection of Trace

Organics drops by half every 2 and A2

years and so if you plot that out we'll

be one picogram per liter by the

2035 one molecule per liter by the end

of the century I don't know where we'll

go after

that so what does it

mean well increasingly I think we know

something is there when we don't know

what it's being there at that level

means

so the question is when is the water

pure when is it

safe this leads us I think to an

essential question in this new age do we

need some kind of new discussion about

risk about when water is

safe but we have problems discussing

risk over the past four decades here in

the US we have developed them refined a

formal risk assessment process to help

us address these unknowns

scientific reviewers have weighed in

weighed in many of them U much brighter

than I many times and a lot of formal

procedures have developed for testing

and extrapolating the test data from lab

animals to people from Days of exposure

decades exposure from exposure of GRS

per leader to exposure picr per leader

and so

on but our risk assessment process can't

keep up with the new chemicals being

generated by Commerce

the process is too low slow and it's too

expensive we're finding ourselves with

an increasingly longer list of

unregulated chemicals unknown

significance as a result inadequate

guidance is presently available to help

the public gain perspective on these

chemicals we operate from the

perspective of

fear to address this dilemma the

Europeans have adopted a precautionary

approach much like the approach we took

the dpps when amble woman weighed in

three decades

ago

necessarily essentially the principle

states that evidence of harm rather than

definitive proof of harm should prompt

policy but of course it's much more

complicated than that and too much

precaution would prevent uh progress and

we certainly don't want to PR progress

so the whole idea is pretty

controversial this cartoon I think does

a good job of capturing the

extremes some would say Europe has

carried precaution to an

extreme how might we achieve better

balance I'd propose four guidelines we

could consider in this new era one I

think we all have to agree we prefer

that we we not have these manmade

chemicals in our environment or in our

drinking water that's the place to start

second we should recognize that this

first principle is not universally

achievable therefore we need a screen to

help us make intelligent investment and

decisions before the subtle science is

available and third in the treatment of

drinking water and waste water we should

seek continuous

Improvement implementing affordable uh

broadspectrum treatment technology as

they become

available and fourth we should find

substitutes for manmade compounds that

persist through our treatment processes

when I say we I don't mean our industry

I mean our nation we need to find

substitutes like we did for detergents

like we did for C uh

cfc's but those things that persist on

water environment and we should give

priority to those that have demonstrated

health

effects I said we need some kind of

screen to help us guide us in our

investments I think perhaps the Minimus

risk would be

useful place to start with that screen

of course the problem is that while we

all agree on the principle of dious risk

or dominous things there's often strong

disagreement as to what level of risk is

in fact dominous so the specifics are

not something we just resolve with signs

it has to be decided by some excepted

Authority a regulator a court of law

perhaps the national

eies but there's Reason for Hope our

Regulators already use a variety of

diminish criteria in managing

risk and Regulators also in the world do

also as an example the FDA generally

a lifetime risk of one million as

the Minimus in their

regulations more than that over the past

five or six decades the developed world

has built a sophisticated

infrastructure of cons uh for the

consideration of Minimus risk where

chemicals are concerned and these are

reflected in guidelines advice

advisories regulations regarding human

exposure to chemicals medicines

agriculture food water in a number of

different

areas and they're used by recognized

authorities like the EPA FDA wh The

Institute of medicine and it it seems to

me that perhaps these could serve as a

launching point for a more comprehensive

set of the Minimus

criteria so what about those

microbiological contaminants we started

with when we began our efforts on water

treatment 160 years ago are they

important

anymore this chart shows the top eight

illnesses in the US this compiled by CDC

all but one are gastrointestinal

diseases that are that could be

transmitted by water today these

diseases are primarily spread in food

and person person

contact but it's pretty evident there

are still plenty of gastro in testal

diseases around in the population and

getting them in our drinking water would

be a great way to spread them around to

a lot more people and um this is what

seems like is going to happen in the

Philippines the next several

weeks I propose to take a moment to go

through the exercise of characterizing

these organisms as Trace organic

compounds torqus that were designed by

nature and and try to Prov a little bit

of of an engineer perspective on this by

comparing them with the the trace

Organics that nature has made with the

trace Organics we've made so this fellow

was refreshing himself with a nice glass

of water let's compare how the presence

of two chemicals might affect him first

let's look at ndma nitrosol De methyl

mean this is a man-made chemical EP has

on its contaminant canidate list

California's Public Health goal is 3

nanog per L 3 *

10us uh G per

lader so let's compare ndma to the neuro

virus neuro virus is the most common

cause this top thing on that list I

showed you uh the elding 50 the the dose

that would cause half of us to get sick

is about 2700 genome copies so say 2700

molecules now let's put these an

equivalent basis first ndma 3 nanog is

about 2.4 * 10 1 1 molecules per

ler and then neur virus so um in

molecules that's about it's 2700

molecules per liter for the ld50 so that

comes

to 2.2 * 10-7 GS per

liter can might suggest we use moles per

liter now I ask you to note the

concentrations for ndma on the left are

about all about 8 to 10 orders of

magnitude lower

than the concentrations for for the nor

virus higher I'm sorry higher

than higher than the con for neuro virus

that's that means they're 100 million to

10 billion times

different now let's look at the

consequences first ndma estimates are if

you're exposed to three NR of ndma and

you're drinking water every day for 70

years you're chance of getting cancer

increases by 1 in a

million remember your chance of getting

cancer is about 1 in four

anyway if you happen to

be one of those one a million uh your

the Fate is yours alone the rest of your

family will be just fine their risks are

still just one

four for n of us if you drink this water

the con ation and with this conation

norovirus in it you have 50/50 chance of

48 Hours of acute gastroenteritis get a

bed we're talking the full circuit thing

intense vomiting explosive di you'll be

sitting on the L with your head in the

sink and in the following days unless

your hygiene is near

superhuman several members of your

family will have the same

experience so as I pointed out earlier

by all men measures of concentration

ld50 for neuro virus is 100 to 10

million times lower than the con the

Minimus concentration for neuro virus

yet the consequence exposure to the

neuro virus seem awfully

unpleasant I think this is special

caution for poal

reuse if if we believe poal reuse in our

future and I I believe it is we need to

continue to invest in our understanding

in the science of pathogens and their

measurement and control because it's

going to be the most important thing we

worry

about so let me summarize our old

Paradigm for Safe Water was to use

natural water sources unaffected by the

activity of

man TR organic compounds we're now

seeing in our water are har dangers of a

new age where the growth of population

and commerce and improvements in endal

chemistry make that natural water

Paradigm

unworkable where to organic compounds

are concerned we need a new paradigm for

Safe Water ultimately

conventional regulations need to be

expanded to address this sort of thing

but in the meantime benchmarks might

exist do exist which might be used to

develop the Minimus

guidelines finally it's the trace

organic chemicals that capture our

imagination but I think it's the

pathogens that are the most important

health risk thank

you

I I don't know if I take questions or

we're

done if someone has a question be if if

you do um I apologize won't be able to

see your hands all I can see is the

light in my

face

questions or

comments good J good job

w

rhs congratulations Clark Prize

recipient so I do want to uh turn your

attention to the the card that rhs had

written and it's in your program

and what I thought was in interesting

about the pro the uh the note was the

number of people that you acknowledged

uh Perry Perry mccardy Mike Kavanaugh

Larry Leong Isham n n who are here

previous Clark prize recipients Jim

Morgan Charlie Amilia George sabag gloss

John criten who's here Carrie how who is

here um but you mentioned your family

and Liz it's been great to get to know

you over the years and thank you for

coming and it's great to have you here

Shane and Brian thank you and your wives

Seline and Lindy who haven't met but

thanks it's good to have you here and um

I want to uh thank Jim Swindon uh as

always and Morton Smith it's good to

have you here representing the

foundation and your families it's good

to have you here uh the Joan Irvine

Smith and Nal Richard G Clark Foundation

has been a great suppor of NWI for over

20 years now and we truthfully honestly

appreciate that support I want to thank

again the trussle family for attending

all the previous Clark PR Clark priz

recipients it's great to have you come

back every year I don't know if people

tell you that but it is it's great to

see you and I want to mention endur

staff Brandy Gina and Roxanna we

couldn't do this without

you we had great support from our

volunteer students as always you're

always welcome

and I want to mention our nwri agencies

we had a number of board members come

and that's fantastic it was good to have

you here so thank you for a great

evening I appreciate all you coming and

we'll see you next year thank

you