The Importance of Environmental Exposure History

Beatriz Tapia, M.D., M.P.H., C.P.H.Assistant Dean of Faculty Development at the

UTRGV School of Medicine,Director of the South Texas Environmental Education and Research (STEER) Program

Outline

• Environmental Health• Current Training for Health Professions

Students• Environmental Exposure impact on Health• Pesticide Research in South Texas• Environmental History Resources

WHAT IS ENVIRONMENTAL HEALTH ?

Environmental health is the field of science that studies how the environment influences human health and disease

www.niehs.nih.gov/oc/factsheets/pdf/e-health.pdf

“ENVIRONMENT” INCLUDESNatural environment Physical, chemical and biological things in our surroundings (air, water, food, soil)Man-made or “built” environmentPhysical structures where people live, work and playConsequences of human alteration to the natural environment (e.g. air pollution)Social environmentLifestyle factors such as diet and exercise, SES and other societal influences that may affect health

www.niehs.nih.gov/oc/factsheets/pdf/e-health.pdf

MEDICAL/NURSING TRAINING

Little time spent on environmental health issues in US medical and nursing schools, training programs There is a need to:Increase clinicians’ awareness Integrate environmental history-taking into practice

Kilpatrick et al, EHP 2002; AAP Handbook of Pediatric Environmental Health, p. 1, 2003.

MEDICAL/NURSING TRAINING

Although many clinicians recognize the importance of taking a work and exposure history to evaluate certain problems, most have had little training or practice in doing so.

Becker 1982; Frank AL 2000; Gehle et al. 2011; Kilpatrick et al. 2002; Merritt 1999; Pope AM and Rall DP 1995; Stotland et al. 2014

Awareness of Environmental Exposures & Impacts Is Growing• Air pollution• Water contamination• Harmful substances in physical

structures and workplaces• Food contamination• Personal care products

Woodruff TJ, et al. Fertil Steril. 2008.

“…exposures of males and females to foreign substances prior to conception can affect both their ability to conceive and the health of their offspring.”

Davis DL, et al.JAMA. 1998

Awareness of Reproductive Effects Is Growing

US Chemical Production and Importation Are High

GAO. 2006; EPA. 2008.

*Among those tested for certain properties, reproductive/environmental effects may not have been assessed.

87K 3K8KApproximate

no. of chemicals

registered for commerce in

US

are produced or imported in

annual quantities of

>1 million pounds

--or one-tenth--have been tested for potential

health effects*

Some Reproductive Effects Are Well Known

Exposure Can Increase the Risk of…

Tobacco smokeMiscarriageInfertilityPreterm delivery

Low semen qualityLow birth weight

Heavy alcohol useFetal alcohol syndromeMental retardation

Behavioral problemsBirth defects

Heavy metals (lead, mercury)

MiscarriageInfertilityMenstrual irregularities

Abnormal spermAltered pubertal onset

Toluene (e.g., in paint thinner, solvents)

Fetal solvent syndrome

DBCP (pesticide)Low sperm count Other male reproductive

effects

Jones HE, et al. Obstet Gynecol Clin North Am. 1998. EPA. 2008. Woodruff TJ, et al. Fertil Steril. 2008.

Welshons WV. Environ Health Perspect. 2003.

Endocrine-Disrupting Chemicals

• Certain pesticides, industrial chemicals & byproducts, ingredients in plastics

Interfere with hormonal levels or functions, including estrogen, testosterone, prolactin, LH, FSH, thyroid, etc. Demonstrated by rigorous animal studies &

epidemiological observations

more…

Translating Population-Wide Risks into Individual Risks

• Clinicians work with individuals, not populations

• Elevated population-wide risks may be extremely small for an individual

Small Effects Can Have Large Significance

Thi i t tl b di l d

Thi i t tl b di l d

160140120100806040

IQ

Mean = 100

6.0 million:“gifted”

130

6.0 million:“intellectual disability”

70Adapted from Weiss B. Neurotoxicology. 1997.

more…

Small Effects Can Have Large Significance (continued)

IQAdapted from Weiss B. Neurotoxicology. 1997.

57%increase in “intellectual disability ”population

Thi i t tl b di l d

Thi i t tl b di l d

160140120100806040

Mean = 9560%

decrease in “gifted”

population

9.4 million:“intellectual disability"

70

2.4 million:

“gifted”

130

NHANES: Chemicals in Pregnant Women

Woodruff TJ, et al. Environ Health Perspect, 2011

Reproduction-Related Effects

“…every child conceived today in the Northern hemisphere is exposed to pesticides from conception throughout gestation and lactation regardless of where it is born.”

Colborn T.Environ Health Perspect. 2006

Pesticide Exposure During Pregnancy among Hispanic Women in South Texas

Research Question:How do pesticide exposures of pregnant women living in the Lower Rio Grande Valley compare with those of pregnant women living in New York City (NYC)? (in partnership with U.S. Hispanic Nutrition Research and Education Center)

Pesticide Exposure in New YorkPrenatal insecticide exposure, birth weight and length among an urban minority cohort. Whyatt, et al. Environ Health Perspect. 2004 Jul; 112(10):1125-32.

• Inner city of NYC has highest pesticide application rates in NY State, principally used for roach control in low-income housing.

• Measured pesticides in dust, air, maternal blood, etc.

Results: Babies born to mothers exposed to organophosphate pesticides had decreased birth length and head circumference. Currently assessing cognitive/behavioral measures up to age seven. N=314Whyatt, et al. Environ Health Perspect, 2004

Pesticide Exposure in South TexasStudy Population:

25 pregnant Hispanic Women, 18-35 y/o, 30-34 weeks gestation, recruited from maternity clinics in Hidalgo County

Inclusion criteria:• Stable residency within drivable distance• Non smoker/no illicit drugs/moderate drinker• No major health problems (DM, AHT, HIV, NS)• Homemakers who spend majority day in home

Pesticide Exposure in South Texas

Methods:• Questionnaire covering demographics, home

characteristics, residential history, and lifestyle• Installation of PUF sampler in home• Two weeks later - follow-up questionnaire • All samples (air and dust) sent for analysis

Pesticides analyzed in home air and dust (~45 total)Organophosphates• Azinophos-methyl• Chlorpyrifos• Diazinon• Ethyl Parathion• Malathion• Methyl parathion• PropetamophosCarbamates• Bendiocarb• Carbaryl• Carbofuran• Fenoxycarb (also IGR)• PropoxurSynergists• MGK 264• Piperonyl butoxide

Fungicides• CaptanSynthetic Pyrethroids• Bioallethrin• Bifenthrin• Cis-permethrin• Cyfluthrin• Cypermethrin• Deltamethrin/tralomethrin• Fenvalerate• Lamda-cyhalothrin• Prallethrin• Sumithrin• Tetramethrin• Trans-permethrin

Pesticides Analyzed (continued)Insect Growth Retardant (IGR)• Fenoxycarb (also carbamate)• Hydroprene• Methoprene

Organochlorines• 4,4’-DDD• 4,4,’-DDE• 4,4’-DDT• Alpha-chlordane• Dieldrin• Gamma-chlordane• Heptachlor• Lindane

Herbicides• Atrazine• Metolachlor• Pendimethalin• Simazinc• TrifluralinOthers• Fipronil• Ortho-phenylphenol• Sulfluramid

Pesticide Exposure in South TexasResults: 68% households reported pesticide use vs. 85%

NYC households 35% used two or more pest control methods 14 pesticides: ortho-phenylphenol in 92% of

home air samples, followed by chlorpyrifos in 80%, propoxur in 76%, diazinon in 72%, and trifluralin in 60%

Pest control methods used and target pests for Texas women who reported pest control measures used in their homes during pregnancy. N=17

ConclusionsResult cont.

Household pesticide exposures during pregnancy in South Texas were similar to those in NYC

In both Hidalgo County and NYC, the principal reason for organophosphate pesticide use were roaches

Offspring of mothers exposed in NYC showed significant neurodevelopmental problems

Neurodevelopmental studies among South Texas children exposed to pesticides are lacking

Studying Pesticide Exposure Has Inherent ChallengesLimitations impeding research:

• Human trials precluded by ethical considerations• Difficulties in assessing impacts• Difficulties in measuring outcomes

Reproductive health &fetal/child

development

Adapted from Hubbs-Tait, et al. Psychological Science in the Public Interest, 2005

Many Complex Factors Interact to Affect the Impact of Exposures

Environmental Exposures and Critical Windows of Susceptibility

Woodruff TJ, et al. Fertil Steril, 2008

Pesticide exposure

Effects on fertility

Spontaneous abortionStillbirthPremature birthLow birth weight/small for gestational age

Developmental defectsReproductive system effects

Mechanisms of action

Bretveld RW, et al. Reprod Biol Endocrinol, 2006

Reproduction-Related Effects: Women

Reproduction-Related Effects: Women

Changes in Menstrual Cycle (1.5 ↑ odds )▪ Longer cycles▪ Missing periods ▪ Bleeding mid cycle

Consequently affecting Fertility!Pesticides: Lindane, atrazine and mancozeb

Farr SL, et al. Am J Epidemiol, 2004

Reproduction-Related Effects: Men

• Testicular damage: Azoospermia, oligospermia Damage to germinal epithelium Genetic alterations in sperm Reduced fertility

• Altered hormone function

Figà-Talamanca I, et al. Occup Med, 2001Whorton MD, et al. Lancet, 1977

Delayed Effects of Exposure

Wigle DT, et al. J Toxicol Environ Health B Crit Rev, 2008

• Preconception• Prenatal• Postnatal (lactation)Exposure

• Childhood and adult cancer• Delayed development• Childhood asthma and allergies• Infections• Postnatal growth effects

Critical windows of susceptibility:

The Barker Hypothesis

Barker DJ. Trends Endocrinol Metab, 2002; Woodruff TK, Walker CL. Fertil Steril, 2008; Woodruff TJ, et al. Fertil Steril, 2008

“Exposures to adverse insults during critical…windows of development can permanently reprogram normal physiologic responses, and thus give rise to…disorders later in life.”

Woodruff TJ, et al.Fertil Steril. 2008

Delayed Development

Strong evidence implicating pesticides and developmental disorders, including PDD-NOS

Organochlorine exposure in utero

• > abnormal reflexes in neonates• ↓Psychomotor ↓mental at 12 months• ↓General cognitive, memory, verbal and

executive functions at 4 yearsRosas LG, et al. Currt Opin Pediatr, 2008

Fetal Origin of Adult Disease

Low birth weight▫ Surrogate marker for poor fetal growth

▪ Linked to coronary artery disease, hypertension, obesity, and insulin resistance

Calkins K, Devaskar SU. Curr Probl Pediatr Adolesc Health Care. 2011

“So What Do I Do?”

• Science regarding environmental exposures and reproductive health is: Primarily based on animal studies Warrants guidance to limit/avoid exposure

• Approach patients on case-by-case basis• Exposure is unavoidable, but specific

changes can make a difference

Expert Medical Advisory Committee on Environmental Impacts on Reproductive Health, 2009

The Environmental Health History

Identify and reduce or eliminate

potentially harmful exposures

Identify and reduce or eliminate

potentially harmful exposures

Identify and reduce or eliminate

potentially harmful exposures

Environmental Health History Should Be Routine

HO

W?

WH

Y?

WHEN?

Vulnerable Stages: Early childhood Puberty Adolescence Preconception planning

(men & women) Pregnancy

Expert Medical Advisory Committee on Environmental Impacts on Reproductive Health. 2009.

Community Home/Hobbies

Socioeconomic

Occupation/School

Personal

One Tool for Conducting an Environmental History: CH2OPS

Adapted from Schettler T. 2009.

CH2OPS: Community

Factories

Landfills

BusinessesHazardous substance spills

Recreational areas

Farms

Adapted from Schettler T. 2009; Expert Medical Advisory Committee on Environmental Impacts on Reproductive Health. 2009.

Community: Guidance for Patients

Learn about/inform patients about community organizations & resources, such as:• Dry cleaners that avoid toxic solvents• Salon products without toluene, phthalates, and other toxic chemicals

• Grocery stores that carry organic productsResource Tip:Download the What We Can Do: Community Efforts to Protect Our Health Tool Kit from the Women’s Health and the Environment Web site

Adapted from Schettler T. 2009; Expert Medical Advisory Committee on Environmental Impacts on Reproductive Health. 2009.

ATSDR CASE STUDIES

Taking an Exposure History, June 2015

https://www.atsdr.cdc.gov/csem/csem.asp?csem=33&po=4

Resource Sites

• Association of Reproductive Health Professionals www.arhp.org

• National Environmental Education Foundation https://www.neefusa.org/

• Agency for Toxic Substances and Disease Registry (ATSDR) http://www.atsdr.cdc.gov/

more…

Resources for Clinicians• Critical Windows of Development

(www.endocrinedisruption.com): Online tool from The Endocrine Disruption Exchange (TEDX)

• ReproTox (www.reprotox.org): Summaries on the effects of >5,000 agents and exposures on pregnancy, reproduction, and development

• TOXNET (http://toxnet.nlm.nih.gov/): Databases on toxicology, hazardous chemicals, environmental health, and toxic releases

more…

Resources for Clinicians (continued)

• American College of Occupational and Environmental Medicine (www.acoem.org)

• Collaborative on Health and Environment (CHE) database (http://database.healthandenvironment.org/)

• EnviRN (www.envirn.umaryland.edu)• Local environmental health specialists• Occupational and environmental health

departments in universities

ARHP Resources on Environmental and Reproductive Health

Learn more at the ARHP Web site:• Click on Environmental and Reproductive Health topic area

• www.arhp.org/topics/enviro-repro-health--Fact Sheet: Environmental and Reproductive

Health Resources for Health Care Providers--Patient handout: Health Matters: The Connection

Between Your Health and the Environment

Summary

• Evidence is increasing of effects of pesticide exposure on reproductive health

• Precautionary approach should emphasize prevention

• Environmental health history and patient guidance should be incorporated into health care for all patients

more…

Summary

• Environmental exposures affecting world’s health and welfare

• Critical windows of susceptibility Preconception to the postnatal periods Childhood Adolescence Adulthood

Summary

Clinicians can help by offering guidance, counseling, and resources:• Incorporate an environmental/occupational history

as part of patient health history• Be aware of risks in your community• Work with community groups to reduce

exposure levels • Provide education and information sources

Questions?

Thank you