Environment and children's health

Does the children population need an increased protection against

environmental stressors?

Motto

Child is not a little adultPrenatal development and infancy in individual time

periods has its own specific risksThe level of health in children's population foresees

the quality of the next generations. The optimal health status of children is fully of the

highest concern for public health.

European Action Plan of Environment and Health

2004 – Children´s Environment and Health Action Plan for Europe (CEHAPE)Aims: 1) To improve the access of children to safe drinking water and

sanitation at home, schools, children facilities and recreation areas until 2020

2) To limit obesity and injuries of children by means of safety environment, physical activity and healthy food including the school meals

3) To improve the quality of outdoor and indoor air (reduction of exposure to dust aerosol, support of heating with clean energetic source, decrease of exposure to environmental tobacco smoke)

European Action Plan of Environment and Health

4) Prevention of diseases caused by physical, chemical and biological environmental factors.

Protection is aimed above all at pregnant and nursing mothers and at the places of usual stay of children.

Identification of risks and their elimination until 2015.

Identification of risks of exposure to carcinogens, mutagens and teratogens including radon, UV radiation, asbestos and endocrine disrupting chemicals (EDC)

Call for more attention to adverse health effects of persistent chemicals, EDC and bioaccumulative compounds and replace them with the more safe compounds.

Increase the research of health risks of nanoparticles, nanomaterials and electromagnetic fields.

Decrease the exposure of children to noise including traffic noise and personal electronic devices.

Pay attention to child labour and exploitation.

European Action Plan of Environment and Health

Protection of health and environment against climatic changes (excessive temperature, support of sufficient amount of drinking water, safe food and sanitationDevelop and strengthen early warning systemImplement and increase educational and public awareness programs for teachers, parents and general population,

Increase and support the participation of adolescents on decision-making processes in the field environment and health. Support the development of the European Environment and Health Information System (ENHIS)Develop a consistent and rational approach to human biomonitoring.

Environmental stressors

Physical: microclimate (temperature, humidity, air circulation), noise, vibration, ionizing (e.g. radon) and non-ionizing radiation (UV, electromagnetic fields), dust particles incl. nanoparticles).

Chemical: acute, subacute, chronic effects, systemic effects on different organs, delayed effects (carcinogenic, mutagenic), allergenic, endocrine disrupting effect.

Biological: microorganisms (legionella pneumophilla), protozoa (ameba ), cyanobacterium (toxins), fungies (mycotoxins), allergens (pollen, mites, insects etc.)

Physical factors - I

Noise - each sound which is annoying or disturbing to some individual.

Sources: traffic, industry, elevators in houses, restaurants, music performances, etc.

Specific health effect –hearing loss (occupational exposure), acoustic trauma

Systemic health effects – adverse effect on vegetative system with predominance of sympathetic nervous system, increase of blood pressure, changes in metabolism, increase of blood levels of lipids and cholesterol, increased excretion of stress hormones.

Worsening of sleeping qualityIt is documented a (a) correlation between incidence of non-

communicable diseases and a level of noise in the night, (b) relation between percentage of persons with the feeling of annoyance and measured noise level a (c) relation between local noise level and percentage of persons with sleeping disturbance.

Noise and children

At present, it is not clear whether children are more vulnerable to noise than adults.

However, children have less control over noisy environment and their leisure activities often involve loud sound sources (noisy toys, noisy communication in groups of children, noisy music etc.

Nonspecific effects: sleep disorders, worsening of communication, stress reaction, poor assumption of oral communication and reading, poor concentration.

Increased risk of injuries in noisy environment (e.g. traffic)

Physical factors - II

Solar radiationUV radiation, rising concern about

sunbathing in the last decades, several winter stays in tropic and subtropical countries, solaria

Adverse health effects:Increased risk of dermal carcinomas (solar

radiation belongs to the human carcinogens - malignant melanoma, basal cell carcinoma)

Increased ageing of skinIncreased risk of cataract

Children and solar radiation

Exposure to solar radiation (UVR) in childhood constitutes a significant risk factor for the formation of dermal tumors. The skin of child is thinner and the level of protective melanin lower. Likevise, the proportion of body surface to BMI is greater.

In spite of the fact that children are more vulnerable, their protection from solar radiation is still insufficient. It depends on fototype of children, education and behavior of parents. Most often, children get sun-burned in their pre-school age.

About 25% of exposure to UVR is realized until the age of 18 y.Alteration of DNA in melanocytes. UVR and

immunosuppressive effects.

Sunbathing in solaria are not recommended in children. Protective agents (creams etc.) are lipophillic, may contain

phthalates and pollute environment. Zn and TiO2 – nanoparticles with ambiguous health risks

Physical factors - III

VibrationTraffic, instruments used in households, (power

saws, scrub-cutters, grass-cutters)Whole body vibration – kinetosis, means of

transport, seasicknessIonizing radiationRadon and its daughter decay products

Elmg radiation (non-ionizing)Radio waves (broadcast, TV)microvaves) (generators, warming ovens)Radar waves

Non-ionizing radiation

2002 - IARC categorises magnetic field with low frequency to the carcinogens of group 2B – possible carcinogen for human based on epidemiologic studies of leukemia incidence in children living in the vicinity of high voltage distribution. However, the associations were weak.

2011 – similar evaluation for elmg radiation with high frequency.

Study from 2004 warned about a 40% increase of risk for gliom in persons who often use cell phone (at least 30 min daily during 10 year period).

Mechanism is till now unknown

Recommendation: limitation of cell phone usage in small children (precautionary principles)

Physical factors - IV

Microclimatic factors:Air temperatureAir humidityAir velocityHeat radiationIt depends on human activity in a given place

Specificity of children: increaed sensitivity to thermal differences, risk of overheating indoor (rooms, cars etc.)

Environmental media (drinking water, air, soil)

Drinking water and its suitability for preparing an artificial food for infants

Nitrates and infant methemoglobinemiaWay of formation:Concentration of nitrates higher than 50 mg/l Microbial contamination of water and sources of

infant food with bactera able reducing nitrates to nitrites.

Presence of not ripe fetal hemoglobin in infants until 3 months of age

Risk of fetal methoglobinemia may happen only in non-breastfed infants

Children and water for recreation

Diarrhoeal diseases of bacterial origins (salmoneloses, shigelloses, campylobacter), protozoa (giardia, cryptosporidia) and viral (VHA, rotaviruses, norovirae)

aerootitis, conjunctivitisMeningoencefalitis caused with amoeba (Negleria

Fowleri) – poorly cleaned swimming-pools

Children, soil, playgrounds

Possibility of children exposure to pathogens in soil: bacteria, (clostridia) protozoa, (amaeba, cryptosporidie, toxoplasma gondii), parasites (taeniae)

Exposure to environmental chemical pollutants:

inorganic (heavy metals - Pb, Cd, As, vanadium), organic (polyaromatic hydrocarbons, dioxins and other chemicals caused with waste combustion)

Increased exposure of children caused by „hand – mouth“ activity

Children and environmental tobacco smoke

Consequences of smoking of pregnant women:Lower birth weight – poorer start to life – higher risk of chroni diseases in adult age Higher risk of allergenic diseasesSmoking of adults in interiors (rooms, cars, restaurants, other places) Exposure to environmental smoke belongs to the factors carcinogenic for humans.In our country, about 30 % of children live in houses with at least one adult smoker. Other problems of passive smoking: increased incidence of respiratory diseases, asthma attacks Increased risk of active smoking in children

Children exposure to environmental chemicals

Exposure of foetus to environmental chemicals in critical windows of prenatal development could result in adverse health effect in the later life period of adultory or adults.

Some chemical pollutants (e.g. Pb, Hg, dioxins) are able to cross the placental barrier and may damage the development of CNS.

Population exposure may result in behavioral problems, hyperactivity, learning disability and depression of IQ.

Possible outcome: decline of quality of further generations.

What environmental stressors can cross placenta?

Lead, organic form of mercury (methylmercury)Polychlorinated biphenyls, dioxins and similar

componentsPolyaromatic hydrocarbons (PAHs)

Possible adverse effects: neurotoxicity hormonal imbalanceExample from the latest literature:Prenatal exposure to lead (neurotoxicity) and ADHD

(Environ. Res. 2013)

Environmental chemical pollutants able to disturb endocrine balance

(endocrine disruptors)Persistent chlorinated organic compoundsPolyaromatic hydrocarbonsCadmiumZearalenon (mycotoxin with estrogen activity)PhthalatesBisfenol A (production of polycarbonates)Perfluorosulphonates (production of fluoropolymeres

- teflon)

Possible effects of endocrine-disrupting chemicals (EDC)

• Simulation of hormonal effects (false positive signals)

• Antagonisms of hormonal effects (false negative signals)

• Alteration of synthesis or metabolisms of hormons (altered signal)

• Modification of receptors for hormonal activity

Chlorinated pesticides (DDT and its metabolites, HCB, b, g -HCH and others)

Polychlorinated biphenyls (PCB)

Polychlorinated dioxins (PCDD) and dibenzofurans (PCDF)

Polybrominated biphenyls (PBB)

Polybrominated dibenzoethers (PBDE – flame retardates)

Persistent organic pollutants (POPs)

Persistent organic pollutants (POPs):

Charakterics:

Persistence in the environment

Transport on long distance

Long biological half-life

Bioaccumulation in food chain

Bioconcentration (biomagnification) in aquatic animals

Deposition in animal fat

Adrevse health effects

Adverse health effects observed on population level

Increasing incidence of hormonally-dependent diseasesIncidence of breast carcinoma has been increasing about 1 % yearly (this type of carcinoma is usually hormonally dependent)Increasing tendencies are observed in the incidence of: endometriosis cryptorchidism prostate carcinoma testicular cancer hypospadia

Adverse healt effects of POPs

• Endocrine disrupting effects (sexual hormons, thyroid gland)

• Carcinogenicity• Neurotoxicity• Chloracne• immunotoxicity• Alteration of glucose metabolism• Alteration of lipid spectrum (increase of

cholesterol and triglycerids)

Long-term health effects in general population

Children are the most sensitive and vulnerable population group (ED-compounds can cross the placenta and are present in human milk)

Neurotoxicity

Reproduction disorders

Hypothyreosis

Worsening of psychomotoric development of children

However, the adverse health changes are mostly transitional.

65

209 255 261 307381

303378

461532

1068

490

1015

1361

0

200

400

600

800

1000

1200

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1600

1992: WHO – coordinated international study- sum of indicator PCB congeners in

human milk, ng/g lipid

Breastfeeding – benefit and risk

• Breastfeeding is of highest importance for the nutrition of Breastfeeding is of highest importance for the nutrition of infants

• Limit values for PCBs and dioxins are established with regard to the whole-life exposure – breastfeeding period represent only several months of the life expectancy.

• The intake of POPs through breastfeeding does not mean the significant increase of body burden in adultery. More important is the transport through placenta.

• Newborns have very small amount of fat so there is not place for deposition. Most POPs are excreted in faeces.

• Half-life in newborns is short – only several (4) months, contrary to adults (5-10 years).

Should we be afraid of chemicals present in human milk?

• Nowadays there is a trend to support breastfeeding preferentially.

• Breastfeeding is of highest importance for the nutrition of the child.

• The reason for the analysis of chemical contaminants in human milk is simply to monitor the exposure and body burden of population and not to regulate breastfeeding.

• For mothers, it is not recommendable to loose their weight after the delivery too quickly.

International regulation activities

Stockholm convention: 22. – 23. 5. 2001

Regulation of 12 components:

Pesticides: aldrin, DDT, dieldrin, endrin, chlordan, heptachlor, HCB, mirex, toxafen

Industrial products: PCB

By-products of industrial and combustion processes – PCDD, PCDF

Other compounds will continue

Phthalates

Do not belong among the persistent compounds, but among ED

They are ubiquitousHealth risk: DBF a DEHFUsage: plasticisers – production of plasts (since 1949)Exposure: inhalation – burning of plastic wastesperoral – transport to the food through package material, in

children hand-mouth activity (toys) parenteral – plastic equipment – dialysis etc.Effects: carcinogenic (2B), hyperplasia of liver, peroxisomal

proliferation, induction of cytochrome P450Biomonitoring: complicated – metabolites in urine

COOH

COOH

Using of phthalates

Necessary for plast production (plasticity, soft products)

Extensive use in different branchesPhthalates are present in many products and articles

of daily use: toys, cosmetics, products of personal care medical and stomatological articles textile wrappig materials and containers for food

and beverages building materials, binding materials,

detergents plasts and upholstery in cars

Biotransformation

Phthalates are not cummulated in human body, but the exposure from the environment is continuous.

They are quickly metabolised in human body to monoesthers with shorter or longer carbon chain.

Primary and secondary metabolites may conjugate with glucuronic acid.

Glukuronides anf free metabolites are excreted with urine.

Detection of metabolites is used in human biomonitoring for exposure assessment of the population. Metabolites are detectable within 24 h

Metabolity DEHP v moči dětí - GM, µg/l

25 25,8 28,1

37,3 37,5 39,5 40,946,3 48,2 49,9 50

58,7 59,6

73,4 74 76,471,1

82,7

0

10

20

30

40

50

60

70

80

90

Levels of two metabolites of DEHP in urban and rural populations in the

Czech Rep.

0

100

200

300

400

500

µg/L

urban rural

mother boy girl mother boy girl

5OH-MEHP + 5oxo-MEHP in urine

Health related limit for children 500 mg/l, for women in reproductive age 300 mg/l

Why children are more vulnerable population group to environmental

pollutants?Exposure of children (food consumption, air volume

per day) is about four times higher that in adults when it is calculated per kg of body weight.

Infants and small children do not have their defense mechanisms and biotransformation processes enough ripe to be able overcome the adverse effect of environmental stressors.

Child is not able to aware the risks comming from polluted environment or from not health life style

Children often imitate the behavior of adults