MARK D
CURRICULUM FOR THE HEALTH SCIENCES IN SOUTH EASTERN EUROPE
Number (unit, topic): U4-T3
Prior review – Status: D
ECTS (suggested):
Title
Health Importance of Environment Protection
Author(s), degree,
institution(s)
Marija Mirosavljev, MD, PhD and
Vera Grujic, MD, PhD
Institute for Health Protection, Novi Sad, Yugoslavia
Vera Grujic, MD, PhD
Institute for Health Protection
Futoska 121
21000 Novi Sad, Yugoslavia
Address for
correspondence
Keywords
Learning objectives
Synopsis (Abstract)
Teaching methods
Specific recommendations
for teacher
fax: +381 021 613-989
E-mail: izzz@eunet.yu
environmental health, risk assessment, risk
managment
It is expected that students and future public health
professionals become familiar with environmental
health risk assessment. This include competence in
health risk characterization and evaluation as a
member of a team as well as a competence in a risk
managment.
This topic covers:
 health hazards identification
 dose/response evaluation and extrapolation data
from scientific studies to population
 assessment of population exposure
 health risk assessment including uncertainty
factors
 risk managment possibilities
 study of literature in small groups
 guided discussion on models and processess of
environmental health risk assessment
 Selection of proper model of health risk
assessment and managment on the base of
collected data
 the topis allows a good combination of
theoretical knowledge with practical skills
 two or three lectures and 5-6 exercises might be
necessary to reach the goals of this teaching
models and process.
Assessment of students
 practical training on a presented model
 workout a model of risk managment working in
a team with other sectors
Health Importance of Environment Protection
Marija Mirosavljev, MD, PhD Vera Grujic, MD, PhD
Institute for Health Protection, Novi Sad, Yugoslavia
Content


Introduction
The basic characteristics of environmental health risks
- exposure of the whole population and geographical distribution of majority of of
cotaminants
- importance of chronic intake of contaminants with low concentration
- toxic effects of contaminants

Possibilities of health risk assessment
- models of health risk assessment
- process of health risk assessment
- health risk managment


Possibilities of health risk assessment in our region – practical example
The role of environment protection in a modern concept of the health care of population
INTRODUCTION
According the concept of modern medical science health presents dynamic balance between
systems within human body and between the body and environment. Stability of this balance is
different in individuals and depends on their health potential, i.e. on the ability to struggle against
the influence of factors which disturb dynamic balance. (1).
The level of health potential is not a static value. There are factors that increase health
potential and these are health resources (healthy life styles, healthy environment, functional literacy
etc.) as well as factors which decrease it, and these are health risks (air, water and soil pollution,
contaminated foodstuffs, risky behaviour etc.). If health risks prevail health risks the result is
increased health potential and increased level of health. The prevalence of health risks influences
decrease of health potential, resulting in the lower level of health and increased need for curative
treatment.
MAIN CHARACTERISTICS OF HEALTH RISKS IN ENVIRONMENT
Health importance of environment contamination primarily reflects in exposure of all
population categories in large geographical areas, encreasing presence of great number of toxic
matters in all media of environment. Environmental contaminants become health hazards for all
with a risk to result in mass effect of negative health.
Disorders of population health that appear as a result of the activity of environmental risk
factors, the most frequently are the effect of long term low doses exposures hazardous matters.
Acute exposures to high concentrations are considerably rear and the most often are accidentally.
Specific population groups that live near the contaminant emission, primarily vulnerable categories
(children, pregnant women, diseased and aged persons) have the increased risk of higher incidence
of serious health disorders. Similar and/or greater risks are present in professional exposition.
For evident expression of pathological condition or diseases in continual exposition to low
concentration of the most of hazardous agents is necessary a long period of time. Apart of the long
term exposition to external factors, cumulation of many toxic agents in human fibres is also
responsible for the appearance of disease with increase of their pathological potential.
The characteristics of population exposition to these risk factors is simultaneous chronic
exposition to great number of hazards which the clear understanding of the specific activity of an
specific risk makes more difficult. The response of the human tissues to exposition is also
dependant on the numerous individual and specific characteristics of human being or group (age,
sex, special physiological conditions, health status, living conditions). Therefore, the right
understanding of health effects of population exposition to toxic matters in the environment is very
complex and difficult at the present knowledge level.
On the other hand, the complexity of this problem is also reflected in permanent emission of
new compounds, with completely unknown effect to health, parallel with the known presence of
very high number of contaminants with long half-life. Expression of their potential toxicity,
cancerogenity, mutagenity or teratogenity is dependant on many factors.
Counting the identified and risk contaminants exceeds the intention of this paper, but it is
necessary to mention that they are present in enormous concentrations in nearly the all
environmental media. For example, we have to mention asbestos, very well known carcinogenic for
lungs and gastrointestinal tract which became ubiquitous in environment and during long period of
unlimited utilisation and consequent emission it contaminated soil, food and water in such a
volume that it became impossible to eliminate existing quantities (2). The similar situation is with
lead which was also widely used and so reached in all parts of environment. Signs of lead
exposition with health disorders are almost found in children age (3). There also have to be
mentioned highly toxic and cancerogenous polychlorinated biphenyls or dioxins, pesticide
residuals, artificial fertilisers, radionucleides as well as many others (4-7).
POSSIBILITIES OF HEALTH RISK ASSESSMENT
It is obvious that medical importance of environmental protection is present within the
intention to identify and quantify limits of risk exposures to environmental contaminants and to
indicate possible health impairments with the final intention to prevent or limit the phenomenon of
disease and invalidity, to improve quality of life and prolong working and living age. Therefore,
since 50's of twentieth century have been developed numerous models for health risk assessment,
and since 1980-s have been improved models of complex quantitative assessments. These models
can enable assessments of specific negative effects to health during exposure to wide scale of
concentrate pollutants in environment, in small doses, which are the most often present (8).
Health risk assessment encompasses process, which integrates the procedure of
identification of hazards to health, the assessment of biological dose-response, the assessment of
population exposure and risk characterisation, i.e. estimation of health disorder incidence in
population.
Health hazard identification both for cancerogenics and non-cancerogenic agents
encompasses experimental, laboratory investigations on animals, during exposition to different
doses of analysed negative effects. It is considered here that investigation results concerning
cancerogenic matters at laboratory animals in higher doses may extrapolate in human tissues but
application of experimental results at human beings in investigation of small exposition doses is
still unclear. These investigations require activation of numerous factors and satisfaction of many
conditions: great number of animal kinds, investigation of great number of different tumours and
different doses of analysed agent. Investigation of health effects of exposure to non-cancerogenic
toxins also require similar conditions (8).
Besides strictly controlled conditions, extrapolation of experimental results from animals to
humans gives certain level of risk which has to be defined in the final risk assessment.
Dose-response evaluation (concentration) of analysed agent the most often encompasses
data extrapolation from experimental studies on animals to humans or extrapolation from studies of
professional exposure to population exposure to the same agent in environment. The greatest part
of risk appears in this extrapolation, for in environment there are low doses of exposure, and there
are biological differences between humans and animals in metabolic ways, distribution ways and
excretion of toxins and differences in response of human tissue concerning the animal. More safety
results have been achieved in the field of physiological and pharmacokinetic models of assessment
(9).
The most acceptable is considered to be the biological model of assessment that quantifies
the number (rate) of cell mutations which should happened in order that malignity would appear
and encompasses the process of appearing and death of target cell influenced by certain dose of
agent. But these investigations are still in progress and results are unreliably (8).
Although from the aspect of population health care knowledge on risky exposition doses are
the most significant, although a lot of financials are put in these investigations, completely reliable
considerations still do not exist.
Exposure assessment is the step in health risk assessment which can be proceeded with
less risk. At present it is possible to measure very precisely the concentration of some chemical in
different media and to assess human intake. However, it is necessary to consider great number of
facts and to have some knowledge on transport, distribution and final effect of certain chemical
which is emitted in environment. Half-life and concentration of certain chemical in environment is
different in different media, depending on exposition to sun, microbial influence in soil and water,
and it can also be dramatically changed. It is known that dioxin vapours, emitted from incinerator
have half-life of only 90 minutes, but deeply in the soil or in the ash they last 50 or 500 years (9). It
is also necessary to consider indirect ways of exposition, for chemicals circulate in nature and reach
in different media and they are very often included in nutritional chains.
Human exposition can be determined the most precisely by measuring very small
concentrations of contaminants in body liquids, body fats, hair and excretes and in this way are
achieved direct and qualitative exposition indicators. However, such measurements are not always
possible and therefore the other mathematical assessment models are also applied.
Apart of the assessment of general population exposure, it is also necessary to assess
differences for specific, target groups where certain techniques are also developed.
Risk characterisation is the most serious part of the health risk assessment. It gives the
basis and enables developing of strategies for public health care and it should be also able to
integrate qualitatively all previous processes, to assess the economic aspects (cost/benefit) and also
to make good assessment of all undefined facts within applied models. Above all, good information
system is necessary between participants in health risk assessment, bodies authorised for strategy
planning, national governments and international bodies and primarily, timely and objective
information of population.
Health risk assessment can be more simple than presented. NOEL model (No Observal
Adverse Effect Level) determines safe value, using results of the most qualitative studies on
animals. The model gives limit for safe intake value for certain contaminant, which should enable
prevention of health impairment. The advantage of this model is fast and easy application. The lack
is that it implicates the signed safety concentrations to be equally safe for all population categories
which surely is not true, so significant uncertainties in risk assessment are expected.
POSSIBILITIES OF HEALTH RISK ASSESSMENTS IN OUR VICINITY
Health risk assessment in population from the environmental contaminants with the
application of scientifically accepted models in the world does not exist in our country. Assessment
of the population exposition volume, which are considered to be the most reliable part of
information in the world, are present in our country as well. However, these investigations do not
offer always enough information, because limited number of parameters are followed up, and very
often insufficient number of samples,
depending on possibilities of the institution, and the investigations are not always sufficiently coordinated on the country level.
In attempt to make health risk assessment, achieved results on certain contaminant
concentrations are the most often compared to maximally limited concentrations. Having in mind
published results on air contaminant measurements in Novi Sad (11), only periodical exceedings of
valid limited emission values for the most of followed contaminants are registered (Tab.1). Only
frequent lead presence in the air is detected in busy traffic arteries. Concerning low regulation,
chemical contamination of drinking water in South Bačka district is determined in 9 % of samples
of purified and chlorinated water and in 93 % of samples of unpurified and non-chlorinated water
in the period from 1994-1999 (12). The most often is determined increased iron, mangane and
ammonia value, and it is assessed that there were not present contaminants of antropogenic origin,
but it was the consequence of the soil structure.
Tab.1. Results of air contaminent measurements, 1990-1999.
Ambient air in Novi Sad
Number of analysis
Parameter
Sulphyroxid
Soot
Nitrogenoxid
29716
45407
4600
Lead
Cadmium
Zinc
916
914
899
Nitrogenoxid (1h)
Carbonmonoxid
Lead
1435
1419
1435
% of measurements above
MLV*
1,89
3,45
0,28
Aerosediment
0,22
1,53
0,0
Air in traffic arteries
0,28
0,63
10,45
* maximally limited value
Tab.2 Percentage of contaminated foodstulfs due to pesticide presence above MLC* in the period
1995/1999.
Pesticides
No of
samples
62
106
28
78
30
304
Year
1995.
1996.
1997.
1998.
1999.
Total
%
of contamin.
1,6
0,9
0,0
1,3
0,0
1,26
* miximally limited concentration
Tab.3 Percentage of contaminated foodstuffs due to heavy metals and arsenic presence in the
period 1995-1999.
Lead
Year
No.
1995.
1996.
1997.
1998.
1999.
Total
61
86
38
88
35
308
% of
contamin.
0,0
0,0
0,0
0,0
2,8
0,56
Cadmium
No.
% of
contamin.
61
0,0
81
0,0
25
0,0
76
6,6
21
4,7
264
2,26
Mercury
No.
% of
contamin.
61
0,0
81
0,0
20
5,0
74
1,3
19
0,0
255
1,26
Arsenic
% of
contamin.
57
0,0
86
0,0
38
2,6
92
0,0
25
0,0
208
0,52
No.
Chemical contaminants of foodstuffs are followed up in very limited list of parameters, as it
is shown in tables 2 and 3 (13). These data resulted in the assessment that environment in our
country is not significantly contaminated and consequently the health risks are not expressed in
such a volume as it is in developed countries. Assessment results of the intake of certain chemicals
through inhalation or ingestion are very rare in our region (14), and there are not sufficient valid
data for all necessary phases of qualitative assessment. Even more rare are proceeded analysis of
certain environmental concentrations in human material (15).
Having in mind above mentioned facts, it is obvious that there is no possibility of population
health risk assessment in our country or at least such level of reliability recommended and accepted
in the world.
PLACE AND ROLE OF ENVIRONMENT PROTECTION IN
CONTEMPORARY CONCEPT OF POPULATION HEALTH CARE
The most important aim in contemporary medicine is to improve and preserve human health
by measures that contribute strengthening of health potential, i.e. by using health resources followed
by simultaneous prevention
and control of health risk. The main approach in health potential improvement of an individual,
group or community is health promotion which make the balance between an individual and
environment , combining individual choice and social responsibility. Its aim is to decrease
inequalities in the present health condition but also to ensure equal possibilities that will enable
people to develop their health potential entirely. It is achieved through healthy environment,
available information, by developing of skills and creating vicinity that will enable realisation of
healthy choices.
It is obvious that health service solely cannot ensure pre-conditions and perspective for
health. Health promotion requires coordinated action of all main subjects: country(government),
health, social, economic and other sectors, non-governmental organisations and voluntary
associations, local authorities, industry, mass media.
Its actions encompass:
1) Formulation of public health policy combining different but complementary approaches
(legislation, fiscal measures, taxation and organisational changes), which will improve positive and
prevent negative health condition.
2) Creation of health and pleasant environment followed by systematic follow up and
estimation of the influence of fast changes in environment to health, synchronised with actions
which will enable their positive influence to human health.
3) Strengthening of social action through determination of priorities, decisions, planning and
realisation of strategy in health improvement which requires entirely and continual information
approach, possibility to learn about health as well as financial support.
4) Development of skills in an individual through information provision, education for
health, development of skills in order to make better possibilities for own health and environment
control as well as to make the right choice that leads to health.
5) Reorientation of health service towards health promotion, parallel with responsibility for
clinic and curative services. It should enlarge its activity field and make it sensitive for cultural
human needs as well. Its activities have to support requirements of individuals and community for
more healthy life and to create ways of co-operation between health sectors and those dealing with
social, economic, physical, biological and other
environmental problems. Reorientation of
health sector also requires stronger orientation towards investigations on health as well as changes
in professional education and creation of entirely needs of individuals as complete personality.
The approach of health as resource, concerning human survival, resulted in the idea that
health systems have to be able to satisfy health and social requirements of humans during the whole
life. The priority is given to primary health care for it has effects where humans live and work,
where problems appear and where they can be solved in the best way. It is for sure that health
systems in future have to be changed fast and they have to be ready to answer various problems,
such as demographic and economic changes, changes in epidemiology and in socio-medical
characteristics and significance of disease, changes in environment. This will require permanent
knowledge improvement of medical workers as well as to be able to work in multidisciplinary
teams, and informed individuals, family and community, determined for health will be the best
guarantee that health will be realised and preserved.
Resources
see reference list
References
1. Šulović V, Jakovljević Đ. Medicina i kvalitet života. Srpska akademija nauka i umetnosti,
Beograd, 1997. Naučni skup sa medjunarodnim učešćem
2. Kashimoto T: Cancer due to asbestosis exposure, Chest 1992; 101 (1): 58.
3. Rosen JF; Adverse health effects of lead at low exposure levels: Trends in the management
of childhood lead poisonong. Toxicology 1995; 97:11.
4. Swanson GM, Ratcliffe HE, Fisher LJ: Human exposure to polychlorinated byphenyls
(PCBs): A critical assessment of the evidence for adverse health effects. Regul Toxicol
Pharmacol 1995; 21 (1) :136
5. Fletcher CL, McKay WA: Polychlorinated dibenzo-p-diozin (PCDDs) and dinezofrans
(PCDFs) in the aquatic environment-a literature review. Chemosphere 1993; 26: 1041.
6. Simonich SL, Hites RA: Global distribution of persistent organochlorine compounds,
Sciencee 1995; 269:1851.
7. LaDou J, Jackson R.J, Howard J: Environmental exposures and control, in: LaDou J:
Occupational and environmental medicine, 2ed, Prentice Hall International (UK) Inc.,
London, 1997, 647.663.
8. Silbergeld EK: Risk assessment: The perspective and experence of the US environmentalist,
Environ Health Perspectives 1993; 101:100.
9. Paustenbach JD: Health risk assessment, in LaDou J: Occupational and environmental
medicine, 1ed, Prentice Hall International (UK) Inc., London, 1997, 766.
10. Paustenbach JD: The practice of health risk assessment in the United States (1975-1995):
How the US and the other coutries can benefit fro the experience. Human Ecolog Risk
Asess 1995; 1:29.
11. Ljikar V, Jevtić M: Kvalitet vazduha i rizici po zdravlje ljudi, u Popović D: Čovek i priroda
– Zdavlje ljudi u Vojvodini, Matica Srpska – Univerzitet u Novom Sadu, 2001, 75.
12. Ljikar V, Jevtić M: Medicinski aspekti kvaliteta vode za piće, u Popović D: Čovek i priroda
– Zdravlje ljudi u Vojvodini, Matica Srpska – Univerzitet u Novom Sadu, 2001, 55.
13. Mirosavljev M, Ljikar V, Mihajlović B, Stanojević S, Stefanović S, Mirilov J: Zdravstveni
rizici od kontaminenata hrane, u Popović D: Čovek i priroda – Zdravlje ljudi u Vojvodini,
Matica Srpska – Univerzitet u Novom Sadu, 2001, 65.
14. Mirosavljev M, Kristoforović-Ilić M, Slavić M, Jevtić M: Estimation of daily ingestion of
pesticide residue through food in Vojvodina, Fourth International Symposium and
Exhibition on Environmental Contamination in Central and Eastern Europe, Warsaw,
Abstracts, 1998.
15. Kristoforović-Ilić M, Monarov E: Xenobiotic residues in human tissues and in daily diet.
16th International Congress on Nutrition, Montreal, Abstracts, 1997: PT 364, 243.