1º Parcial – INGLÉS I
1) ENVIRONMENTAL RADIATION
(I) Nowadays, a number of countries have environmental radiation monitoring systems, so they are able to
obtain information on the possible harmful effects on populations of radioactive fallout from nuclear weapon
tests. They can also monitor the surroundings of nuclear installations, nuclear power stations, research
reactors, fuel processing plants, etc.
(II) At the present time, these systems are no longer the responsibility of national atomic energy
commissions alone. This responsibility is now divided and, in some countries, public health authorities,
together with producers and users of radioactive substances, are becoming progressively involved in the
monitoring of radioactivity levels in the environment. All of them are deeply concerned with preventing the
radioactive contamination of the population.
(III) Two types of monitoring should be recognised: 1) global or national monitoring; and 2) monitoring of
the nuclear-installation surrounding controlled zone. Samples of air, water, soil, food and biological tissues
have to be collected in different places and analysed for their content of different radioactive compounds.
(IV) It would not be advisable to evaluate the risk to population by physical monitoring alone and further
research on the biological effects of low levels of radiation and radioisotopes on human beings would be
required. Biological studies must be based on the evaluation of the genetic, carcinogenic and other somatic
effects of radiation on populations. A promising method in this field could be the study of chromosome
aberration rates in radiation-exposed population groups.
(V) There is a common problem in evaluating data from national monitoring systems: their incomparability.
This difficulty is caused by the use of different methods for measuring and interpreting results. To overcome
this difficulty, many international agencies are now developing programs of intercomparison measurements
of environmental samples in different countries.
(VI) Therefore, the evaluation of present and potential hazards to the population from different sources of
radiation is being progressively based on accepted international standards and norms; these are being
enforced by national systems of surveillance of global and local radioactive inspection. They aim at
controlling the emissions from consumer goods, industrial and medical sources of radiation, nuclear
installations, etc.
1) Elabore un breve resumen del texto (no más de 2 oraciones por párrafo)
2) Traduzca párrafos (I) a (V)
3) Indique con SÍ las oraciones que expresen información contenida en el texto y también el
párrafo donde se encuentra dicha información.
a. Hay más de un organismo involucrado en el control de los efectos de la radiación sobre el medio
ambiente.
b. Se proponen algunos métodos para encarar la evaluación de la radiación recibida por la población
que resulta del uso de equipos médicos.
c. Los organismos que monitorean radiaciones han previsto la posibilidad de accidentes en los que la
radiación puede extenderse más allá de las fronteras de un país.
d. Es importante que los monitoreos incluyan estudios relacionados con los efectos biológicos de la
radiación.
e. Los métodos de medición de radiación se estandarizan enviando muestras de cenizas de huesos a un
laboratorio central.
f. En general, los países tienden a colaborar en el establecimiento de estándares internacionales que
permitan evaluar la contaminación por radiación.
2) HEALTH HAZARDS OF THE HUMAN ENVIRONMENT
 Air: sources and types of pollutant
The general concept of pollution as a consequence of human activity suggests an
activity-based classification necessary for interpreting the resulting pollution.
Atmospheric pollutants have been considered in this chapter in relation to their
production by combustion sources, specific industrial activities, certain community activities,
and personal habits, such as smoking. Combustion sources include: a) power plants and coal- or
oil-fired domestic heating equipment; they produce sulphur oxides, nitrogen oxides, and
particulate matter. These may differ from place to place with respect to physical composition
and chemical characteristics; and b) motor vehicles; these produce a photochemical oxidant type
of pollution and pollution by carbon monoxide and lead.
Historical conditions have affected the degree of importance of pollution problems
and the kinds of available air pollution data. In western society, man-made contamination of
community air has been increasing since the 14th century with the change-over from wood to
coal as a source of energy. Air pollution –from household heating- has always been
synonymous with smoke and sulphur dioxide, but their effects on indoor air have often been
underestimated.
The tremendous increase in the use of petroleum products, particularly in petrolpowered motor vehicles, has produced a new type of pollution. The internal combustion engine
discharges carbon monoxide, lead, nitrogen oxides and assorted hydrocarbons into the air only a
few feet from the breathing zone of the population. Under conditions of poor natural ventilation
and strong sunlight, a complex serious of reactions takes place, and these lead to the formation
of “photochemical oxidants”.
Air pollution from motor vehicles in developing countries does not yet reach the
magnitude of that in highly industrialized countries. Nevertheless, urbanization and
industrialization are developing fast and the contribution to air pollution from motor vehicle
emissions, especially when they are not very well maintained, could increase very rapidly.
Consequently, the resulting pollution could soon be out of proportion to the number of vehicles
on the roads.
1) Haga la traducción de este texto.
2) Con información del texto y usando sus propias palabras, responda:
a)
b)
c)
d)
e)
f)
Qué tipos de contaminación han de tratarse en el capítulo mencionado?
Qué “combustion sources” han de considerarse?
Qué cambio importante se produjo a partir del siglo XIV y cómo afectó ésto al medio ambiente?
Cuál es la “new type of pollution” que menciona el texto?
Cómo se forman los “photochemical oxidants”?
Qué factores aumentan la contaminación a partir de vehículos en los “developing countries”?
3) Diga cuáles de estas afirmaciones son Verdaderas o Falsas. Corrija las falsas.
a) Los contaminantes conocidos como “particulate matter” presentan características uniformes en
distintos ambientes.
b) No se ha valorado adecuadamente el aporte doméstico a la contaminación del aire.
c) Las emisiones de los vehículos consisten en CO.
d) La luz solar es la responsable de la formación de los “photochemical oxidants”.
e) El aumento de la contaminación en los “developing countries” depende tanto de la cantidad
como de la calidad de los vehículos.
3) AIR POLLUTION AND HEALTH: GENERAL CONSIDERATIONS
Interpretation of health reactions to pollution depends on evidence from epidemiological and
toxicological studies that are now being carried out.
Epidemiological evidence can quantify responses for providing the necessary connecting link between
air pollution and people health. Toxicological evidence is used as complementary information,
because it can be gathered under well-controlled and defined conditions, and so it would be able to
provide causation conclusions. However, its relevance to the natural setting is now in doubt. Both
types of evidence are needed to form a reasonable judgement about the health effects of air pollution.
In addition to general environmental exposure, specific exposure results from tobacco smoke, workplace air and household heating and cooking fumes. These additional sources should be carefully
considered before drawing conclusions about the relationship between air pollution and health.
Cigarette smoking is an especially troublesome complication in the epidemiological analysis of
community air pollution. In view of the major causal role that cigarette smoking may have in chronic
respiratory disease and possibly in cardiovascular disease, researchers ought to adjust for the effects of
smoking before the effects of community air pollution on health can be evaluated. However, studies of
smoking and health could point to reactions that are important to study in relation to community air
pollution. Non-smokers may be exposed to significant carbon monoxide concentrations when they are
in smoke-filled rooms. According to the lenght of exposure, such concentrations might be harmful to
health, particularly in the case of persons who are suffering from chronic pulmonary and coronary
heart disease.
Similarly, experience with pollutants under occupational conditions would be a limited source of
information for assessing the harmfulness of various forms of community air pollution, because
occupational exposures are limited to a certain numbers of hours per day and can be directly altered or
controlled when damage to health is occurring.
1) Explique muy brevemente de qué se trata el texto.
2) Traduzca el texto completo.
3) Diga si los siguientes enunciados son verdaderos o falsos (señale en el texto la evidencia
de sus respuestas)
a) Los estudios epidemiológicos sobre contaminación son suficientes para establecer una
relación entre contaminación y salud humana.
b) No se sabe con certeza si la evidencia toxicológica es importante en el caso de ambientes
naturales.
c) La contaminación ambiental en general es afectada por factores particulares.
d) Las posibilidades de controlar la contaminación en los lugares de trabajo son buenas.
e) Está comprobado que el monóxido de carbono a ciertas concentraciones daña la salud.
4) Responda las siguientes preguntas:
a) Qué aportan a los estudios sobre contaminación los dos tipos de evidencia que se
mencionan?
b) Qué aportes particulares a la contaminación se mencionan?
c) Cuál es el papel del cigarrillo en la contaminación ambiental?
2º parcial – Inglés I
1) THE BACTERIOLOGICAL QUALITY OF DRINKING WATER:
 DISINFECTION EFFICIENCY
The comparative efficiency of disinfectants may be expressed in terms of either the
relative concentrations that are needed to attain the same rate of disinfection or the
relative rates of disinfection that are produced by the same concentration of disinfecting
agent. However, the different nature of the microorganisms and the difficulty of
standardising test conditions, such as pH, temperature and the chemical characteristics of
the water, do not allow generalised statements about the comparative efficiencies of
different disinfectants. Within these limitations, disinfecting agents may be grouped
according to their efficacy. Thus the use of chlorine, chlorine dioxide or ozone is
preferable, yet for chlorine the pH should be less than 8.0. Chloramines are only slowly
biocidal, so their use as primary disinfecting agents for water-treatment purposes is not
recommended, yet they may be used for the maintenance of residuals in distribution
systems where the contact time is longer.
Similarly, in decreasing order, the relative resistance of different types of microorganisms
and their probable survival may be listed as follows: protozoan, cysts, enteroviruses,
enterobacteria. Yet there are distinct differences in the time required to inactivate
enteroviruses as compared with enterobacteria, the minimum conditions of disinfectantresidual and contact-time required to ensure a microbiologically safe water supply can be
achieved readily. It is therefore recommended that water from potentially polluted
sources should always be disinfected. This would ensure inactivation of certain
organisms, including some viruses, which may be relatively more resistant than faecal
indicator bacteria.
1) Haga la traducción de este texto.
2) Elabore un resumen teniendo en cuesta estos puntos: a) formas de encarar la
eficiencia de desinfectantes b) inconvenientes para comparar las eficiencias de
distintos desinfectantes c) ejemplos de desinfectantes y de organismos a eliminar
d) diferencias entre enterovirus y enterobacterias.
3) Diga si estas afirmaciones son verdaderas o falsas y corrija las falsas:
a) Existe un consenso generalizado acerca de la eficiencia con que actúan los diferentes
desinfectantes.
b) El cloro es mejor desinfectante que la cloramina.
c) Para ser efectiva, la cloramina requiere mayor tiempo de contacto.
d) No siempre es necesario desinfectar el agua contaminada.
e) La eliminación de indicadores fecales puede no asegurar la eliminaciónntotal de
contaminación.
2) INGESTION OF NITRATE FROM WELL WATER BY VILLAGE PEOPLE
IN INDONESIA
[According to the Health Organisation recommendations drinking water should not
contain more than 50 mg /L of nitrate, for it can cause infant methaemoglobinaemia after
conversion to nitrite in the gastrointestinal tract; links to other diseases have also been
suggested. Nitrate pollution of groundwater is an increasing problem in many parts of the world.
Yet in many situations this problem stems from the use of nitrate fertilisers in intensive
agriculture, it also occurs naturally in certain arid environments such as central Australia. The
most significant threat from nitrate occurs in village situations in the developing world where
conditions of relatively primitive sanitation prevail. We report extensive surveys of the nitrate
concentrations in wells at many locations in Java and Lombock; these reports indicate that
millions of people in densely populated villages are drinking and cooking with water that
contains nitrate concentrations in excess of the World Health Organisation’s guideline value.
Most of this nitrate arises because of the nature of the sanitation in villages, whereby sewage is
discharged into the soil and the nitrogen is nitrified to nitrate which leaches into the
groundwater.
Two major surveys, which involved sampling wells in villages over a large part of East
Java, were done in July 1991 (dry season) and February 1992 (wet season). The methods of
collection and nitrate measurements have been reported previously. There was considerable
local and regional variation in nitrate concentrations. In areas of relatively similar population
density, this variation was related both to soil permeability and the nature of the aquifer. In
permeable soils with a medium to deep water table, nitrate concentrations were higher than in
areas with heavy clay soils and/or a shallow water table]. Shallow wells (less than 2 m depth)
almost invariably had low nitrate concentrations, probably partly because of denitrification in
the topsoil and partly due to the fact that the nitrogen from septic tanks which are deeper than
the groundwater table would be unlikely to nitrify significantly due to anaerobiosis.
A subsequent, separate, survey of the district of Purworejo in central Java revealed
invariably low or negligible nitrate concentrations. The reason for this may be a combination of
relatively low population density, high groundwater flow generated by the mountains to the
north and shallow aquifers in the coastal region. There was not only enormous variation
between regions and settlements, but also within them. A detailed study has been made of such
temporal and spatial variations in Kotagede.
1) Decida para cada una de las afirmaciones siguientes la opción correcta:
a. El nitrato es perjudicial para la salud
1) en sí mismo
2) cuando se convierte en nitrito
3) en asociación con otras enfermedades
b. La contaminación por nitratos surge de
1) el uso de fertilizantes
2) condiciones sanitarias
3) combinación de estos y otros factores
c. En suelos permeables con niveles freáticos de medio a profundos las concentraciones de
nitrato son
1) las más altas
2) no se dispone de datos
3) mayores que en suelos arcillosos y/o
niveles freáticos poco profundos
d. En Java central las concentraciones encontradas fueron
1) muy altas
2) bajas o despreciables
3) variables según el distrito
e. En este estudio no se considera como factor causante de bajas concentraciones de nitrato a
1) habitantes/unidad de superficie
2) acuíferos poco profundos
3) prácticas agrícolas
2) Marque con una tilde las oraciones que indican información que se puede
encontrar en el texto.
a.
b.
c.
d.
e.
Valores aconsejados de concentración de nitrato en agua potable.
Enumeración de enfermedades asociadas a la presencia de nitrato
Métodos de recolección de muestras
Causas probables de la nitrificación de los suelos
Datos de pozos profundos
3) Traduzca la parte del texto encerrada entre corchetes.
3) LINKS BETWEEN EXPOSURE TO ENVIRONMENTAL FACTORS AND
CANCER
A reliable cancer monitoring system should attempt to discover associations between:
 exposure to a suspected environmental factor
 a change in the frequency of a specific cancer. This could lead to the investigation of
previous exposure to environmental factors, yet there are many difficulties with such an
approach due to the lack of easily retrievable specific data on previous exposures.
Data on exposure to environmental factors may be available for either a general
population or individuals, yet it may be difficult to estimate variation in individual exposure
from general population data. Besides, there are considerable differences in the exposure of
populations as a whole, not only between countries in different stages of industrialization, but
also between the different geographical regions of a country or continent.
In the case of individual exposures, priority should be given to a) in utero exposures
and b) industrial exposure, for they may give rise to cancers with shorter latent periods. The
selection of environmental factors will be influenced by the cost of data retrieval, the duration of
exposure, the presence or absence of interfering exposure variables and the possibility of
subsequent measurement of cancer occurrence, both in exposed groups and in non-exposed
controls.
Data on (a) may be obtained from three main sources: I) The WHO Drug Monitoring
Programme: they have recorded both dosages of drugs administered and incidence of congenital
abnormalities II) Data on exposure to selected drugs. For example, in countries with a national
health service, it should be possible to identify both all women who have been receiving certain
drugs and their offspring, either through national record linkage systems, birth registers or
hospital records III) Registers of the offspring of women in certain industrial occupations.
In monitoring industrial exposures, it is desirable to select industries in which the
processes used have remained the same over fairly long periods and workers who have not
changed jobs frequently. Case et al. obtained lists of all men who had been employed in certain
sections of the chemical industry. They were divided into groups according to likely exposure to
some chemicals. Men who had died from cancer of the bladder were found by scrutiny of death
certificates. Mortality rates for the various groups were then compared with the national
mortality experience.
Data from cancer incidence registries will probably provide an earlier and more
sensitive indication of carcinogenic risk than mortality data. However, mortality data have been
useful in many areas where cancer incidence registries do not exist.
a.
b.
c.
d.
e.
f.
1)Traduzca el texto
2)Con información del mismo complete estos enunciados, que representan un
resumen.
El texto destaca el valor de relacionar -------------------- con ---------------------Para poder hacerlo, se pueden obtener datos de ------------------- o ------------------------------.
Los estudios sobre -------------------------presentan un inconveniente: -----------------------------En este texto se desarrolla en detalle el tratamiento de datos obtenidos de -----------------------Esta perspectiva, a su vez, incluye dos tipos de exposiciones: -------------------- e ----------------Estas tienen la particularidad de ------------------------------------
g. Para el tipo de exposición -----------------------, se pueden obtener datos de -----------------------, -----------------, y -----------------------------------h. Para monitorear el tipo de exposición ----------------------, se mencionan dos factores importantes
a tener en cuenta: ----------------------------- y --------------------------------i. Los registros de incidencia de cáncer pueden resultar importantes porque ------------------------j. No obstante, en ciertas situaciones, como por ejemplo --------------------------------, puede resultar
conveniente utilizar --------------------------------------------




3) Diga si estos enunciados son verdaderos (V) o falsos (F)
La exposición de poblaciones a cancerígenos no depende de la región geográfica que se considere.
En el caso de mujeres embarazadas expuestas a ciertas drogas, es importante el seguimiento a su
descendencia
Los estudios de exposición en poblaciones permiten deducir datos precisos aplicables a los
individuos.
Si no existen registros de incidencia de cáncer, los registros de mortalidad adquieren más relevancia.
Los grupos en la experiencia de Case se formaron de acuerdo con la incidencia de cierto tipo de
cáncer.