Vulnerability of Children to Environmental Assaults

Philip J. Landrigan, MD, MScMount Sinai School of Medicine

New York, USA

Workshop on Environmental Threats to the Health of Children in the Americas

Lima, Peru April, 2003

Children Today are Surrounded by anEver Increasing Number of Chemicals

Synthetic Organic Chemical Production

Most of the chemicals to which children are exposed have not been properly

tested for toxicity

• 80,000 + chemicals in commerce• 2,863 produced or imported in quantities of 1 million p80,000 + chemicals in commerce• 2,863 produced or imported in quantities of 1 million pounds or more per year (high production volume [HPV] chemicals)• No basic toxicity information is publicly available for 43% of HPV chemicals• Full information on toxicity is publicly available for only 7% of HPV chemicals

--EPA: Chemical Hazard Data Availability Study, 1998

Children are Especially Vulnerable to Environmental Toxins

“Children are not Little Adults”

• Greater exposure pound-for-pound• Diminished ability to detoxify and

excrete many chemical toxins• Heightened biological vulnerability,

e.g., thalidomide, DES• More years of future life

US National Academy of Sciences, 1993

Patterns of Disease in Children Change

as Nations Undergo Transition to Industrialization

Infectious diseases exert a less powerful influence over patterns of disease and

deathChronic diseases become increasingly

importantThis phenomenon is termed the epidemiological transition

The Epidemiolgical Transition in the United States

The predominant causes of illness, hospitalization and death among children in the developed nations

today are chronic diseases of multifactorial and incompletely

understood etiology

“The New Pediatric Morbidity”

Evidence is accumulating that environmental factors

contribute to the causation of these diseases

Examples of the New Pediatric Morbidity

AsthmaPediatric Cancer

Birth defectsNeurodevelopmental disabilities

Childhood Cancer (Age 0-19), Age-Adjusted Incidence and Death

Rates, 1975-1996

Source: Pediatric Monograph 1999, Surveillance, Epidemiology, and End Results Program Division of Cancer Control and Population Sciences, National Cancer Institute.American Cancer Society, Surveillance

Research

U.S. Incidence of Testicular Cancer

The overall incidence of testicular cancer rose

substantially in the United States from 1973 to 1996. Specifically rates in white

males increased 51.2% over that period, while rates for

black males rose only 17.3% (the latter increase was not

statistically significant). While undescended testes,

inguinal hernia, and prenatal factors have been implicated as possible risk factors, the

cause of the trend in unknown.

Case Study in Developmental Disabilities - Lead Poisoning

A report from Queensland, Australia in 1904 described an epidemic of lead poisoning in young children.

Clinical and epidemiologic investigation traced the source of the outbreak to the ingestion of lead-based paint by children playing on verandahs.

This report led to the banning of lead-based paint in many nations, although not in the United States until 1978.

Clinical Lead Poisoning

Coma and convulsionsPeripheral neuropathy

Kidney failureAnemia

Subclinical Lead Poisoning

Decreased IQ

Altered behavior

Slowed nerve conduction

Elevated uric acid

Elevated FEP

Subclinical Toxicity

… the concept that relatively low dose exposure to certain chemicals … may cause harmful effects to health that are not evident with a standard clinical examination. The underlying premise is that there exists a continuum of toxicity, in which clinically apparent effects have their asymptomatic, subclinical counterparts.

Population Impact of Subclinical Toxicity

Population Impact of Subclinical Toxicity

Subclinical toxicity has become a widely recognized

phenomenon in Children’s Environmental health

•Lead•Methyl Mercury•Polychlorinated biphenyls (PCBs)•Certain pesticides (probably))

Children’s Environmental Health -The International Dimension

The export of toxic chemicals and hazardous processes from the industrially developed to the

developing nations of the world has the potential to profoundly

change patterns of morbidity and mortality, especially in children

Examples of the International Spread of Toxic Chemicals

• Bhopal • Asbestos export• Export of “banned” pesticides• Arsenic in Bangladesh• Pesticides in central Asia• Export of hazardous waste

Bhopal, India:

A Sentinel Event

Bhopal, India

Outside Carbide Factory. Bhopal, India

Bhopal, India

The International Spread of Lead in Gasoline

• Lead was first added to gasoline in 1922• By the 1970s, almost all gasoline produced worldwide

contained lead• In the USA, peak annual consumption was almost

200,000 tons (mid-1970s)• A disaster for public health

Recognition of toxicity to children led to removal of lead from gasoline

• led to removal of lead from petrol

Lead used in gasoline declined from 1976 through 1980

Year

1975 1976 1977 1978 1979 1980 1981

30

40

50

60

70

80

90

100

110

Gasoline lead

Lead

use

d In

gas

olin

e(1

000

tons

)

Source: Annest, Pirkle, Makuc, et al., Chronological trend in blood lead levels between 1976 and 1980. NEJM 1983; 308;1373-7.

Blood lead

Year

1975 1976 1977 1978 1979 1980 1981

30

40

50

60

70

80

90

100

110

9

10

11

12

13

14

15

16

17

Gasoline lead

Lead in gasoline and lead in bloodNHANES II, 1976-1980

Blo

od le

ad le

vels

(g

/dL)

Lead

use

d In

gas

olin

e(1

000

tons

)

Source: Annest, Pirkle, Makuc, et al., Chronological trend in blood lead levels between 1976 and 1980. NEJM 1983; 308;1373-7.

1974 1976 1978 1980 1982 1984 1986 1988 1990 1992

2

4

6

8

10

12

14

16

18

Blo

od

lead

leve

ls (

g/dL

)

0

1994 1996 1998 2000

Blood lead levels in the U.S. population 1976 -1999NHANES II, III, 99+

YearSource: CDC. National Report on Human Exposure to Environmental Chemicals, March 2001

Phase Out of Lead Worldwide

The beneficial effects of the removal of lead from petrol were seen in the following countries:

• USA• Western Europe• Australia• Canada• New Zealand• South Africa

• China• El Salvador • India• Mexico• Thailand

The International Export of Asbestos

Trends in World Production of Asbestos

Year Production (tons)

1963

1973

1978

1983

1988

1993

1994

1995

1996

2,922,000

4,614,000

5,159,000

4,276,000

4,323,000

2,650,000

2,410,000

2,308,300 (a)

2,140,000 (a) (a) Chrysotile only.

World Production of Asbestos by Country (tons), 1995

RussiaCanadaChinaBrazilZimbabweSouth AfricaGreeceSwazilandIndiaUnited StatesColombiaRomaniaYugoslavia

1,000,000510,800250,000180,000145,000100,00050,00030,00025,0009,0005,0003,0001,000

Principal Chrysotile Consuming Countries in 1994

Nation Annual usage (tons)Russia

China

Japan

Brazil

Thailand

India

South Korea

Iran

France

Indonesia

Mexico

Columbia

Spain

USA

Turkey

Malaysia

South Africa

TOTAL

700,000

220,000

195,000

190,000

164,000

123,000

85,000

65,000

44,000

43,000

38,000

30,000

29,000

29,000

25,000

21,000

20,000

2,021,000

Asbestos is Known to Cause the Following Diseases:

• Lung Cancer• Malignant Mesothelioma• Asbestosis• Other Malignancies

On the basis of these facts the Collegium Ramazzini has called for an international ban on all uses of asbestos. ICOH has

joined the Collegium Ramazzini in calling for this ban

Domestically Forbidden Pesticide Exports from USA, 1997-2000

• Products unregistered in the U.S. were exported at an average rate of 16 tons per day

• 57% of products were shipped to developing nations

• Over 21% of products were shipped to Belgium and the Netherlands

• The rest (22%) of products were shipped to unknown destinations, probably also developing nations

• Largest-volume chemicals exported– Butachlor (nearly 14 million pounds)– Carbosulfan (10.2 million pounds)

The WHO Program in Children’s Environmental Health

• An extremely positive development• The theme this year of World Health

Day is “Healthy Children in Healthy Environments”

The Bangkok DeclarationWe will have to continue to join together as we do today, to continue sharing our knowledge, experience, and support. This conference is a call to governments, civil society, the private sector, and the whole international scientist community to renew our commitment to children’s health by advancing a new vision for the 21st century – a vision in which every child has a healthy life and a clean environment.

Professor Le Hung LamHanoi School of Public Health, 2002

Actions Needed for Prevention

• Child-Protective Risk Assessment• Child-Protective Regulation• Right-to-Know Legislation• Children’s Environmental Health research• Training programs• Increased emphasis on the Precautionary

Principle – Presume that children are more vulnerable in the absence of evidence to the contrary

• International Program in Children’s Environmental Health

A New Direction in ResearchNational Children’s Study

• A multi-year prospective epidemiological study to examine the influence of children’s early life exposures to environmental toxins

• As many as 100,000 children followed from before birth to at least 18 years of age

• Explore simultaneous impact of many risk factors on the long term health of children

Critical Research Questions to be addressed through the

National Children’s Study

• Contribution of indoor and ambient air pollution to the origins of asthma

• Environmental causes of developmental disabilities in children

• Effects of endocrine disruption

• Causes of the rising incidence of certain pediatric cancers

Summary

What are Children?

• Our children are the current inhabitants of a developmental stage through which all humans must pass

• The protection of children is essential for the sustainability of the human species

• They are our future

Center for Children’s Health and the Environment

M o un t Sin a i Sch o o l o f M ed icin e