Published on 27/12/2011
Environment and health
The definitions of “environment” are subject to variations. They can cover anything that is not genetic, therefore including social factors and behaviours. The field of environmental health, which pertains to the relationship between all the aspects of health and all these factors, is therefore quite large. In addition to this specific aspect related to the scale of the field in question, environmental health has some unique features that make it more difficult to study:
- Medical conditions in which environmental exposures play a role are frequently multifactorial;
- Exposures can be multiproduct, multichannel and multi-risk;
- Exposures are often weak but chronic and often affect a large portion of the population, if not the entire population;
- The latency between exposure and health effects is significant;
- The relative risks analyzed are low and difficult to highlight, but the portion attributable to the environment of many medical conditions can be high due to the exposure’s high prevalence.
- Look up InVS publications on this topic
Air pollution and health
In France as in other countries atmospheric pollution is a public health concern, despite the adoption of guideline values and more stringent emission standards, better surveillance of air quality and a (sometimes significant) drop in the levels of certain pollutants.
In 1997 the Air and Health Surveillance Program (PSAS) was implemented in nine major French cities (Bordeaux, Le Havre, Lille, Lyon, Marseille, Paris, Rouen, Strasbourg and Toulouse). The program is part of the legislation on air and the rational use of energy (LAURE) promulgated on 30 December 1996, which stipulates under Section 3 that “… the State shall ensure… air quality surveillance and… its effects on health.” The law also provides for Regional Plans for Air Quality (PRQA), whose purpose is to lay down guidelines aimed at “preventing, reducing or attenuating the effects of atmospheric pollution”, as well as Plans for the Protection of the Atmosphere (PPA) in cities of more than 250,000 inhabitants. To achieve this, they need to rely on an assessment of the effects of atmospheric pollution on health and therefore require adequate epidemiological tools.
In this respect, the French Institute for Public Health Surveillance is required to maintain and coordinate nationwide activities on the epidemiological surveillance of the health impact of urban atmospheric pollution in the short and long run, and coordinate those activities with European mechanisms. As a result, the Air and Health Surveillance Program is part of InVS’s Department of Environmental Health.
In particular, quantifying long-term effects in France is still based on the results of a small number of US studies, in other terms the question remains regarding the validity of extrapolating these risks to European countries. As there appears to be appreciably more long-term effects than short-term risks, connections between exposure and long-term risks in France must therefore be developed.
In preparing the European Environment and Health Action Plan, human biosurveillance was defined as “surveillance of humans using biological indicators called “biomarkers”, capable of revealing environmental exposures, diseases and/or disorders or any genetic predisposition, and the study of any connections that might exist between them.” The term “biomarkers” includes exposure, effect and susceptibility biomarkers.
For example, a biomarker might be defined as a chemical or the chemical’s resulting products present in the human body (exposure biomarkers). Describing the concentrations of a given biomarker in the organism is usually referred to as “uptakes”. A biomarker can also be the sign of a biological response to the chemical in question (effect biomarker).
Biosurveillance helps to monitor the presence and effects of chemicals on the organism, such as environmental pollutants. In practice, the idea is to measure biomarkers in the body’s fluids and tissues (blood, urine, hair, saliva, breast milk) that might indicate exposure to substances that are toxic for human health or their effects on the human body.
In other terms, biosurveillance is an important tool in evaluating the level of exposure to chemicals in the environment. It improves knowledge on exposures thanks to a direct assessment of total exposure of humans to environmental pollutants. This assessment includes the various sources and routes of exposure. Biosurveillance also takes account of individual physiological differences (respiration, metabolism, etc.) as well as behavioural factors and the activities of each and every individual (microenvironments, hygiene, use of consumer products). This tool provides the knowledge needed to better evaluate and manage health risks posed by chemicals.
Carbon monoxide poisoning
Implementation of the surveillance system for carbon monoxide poisoning, coordinated by the InVS, was the result of a “brainstorming” initiated in the 2000s by health authorities to combat carbon monoxide poisoning. The carbon monoxide poisoning surveillance system was extended to the entire territory in 2005.
Cold temperatures and health
Cold temperatures affect health at various levels: directly by causing hypothermia for example, or indirectly in cases such as carbon monoxide poisoning. Unlike heat which has rapid effects on the organism, cold weather can have either rapid effects (hypothermia, cold air-induced asthma, etc.) or more or less delayed effects (strokes, respiratory infections, etc.). Furthermore, flu epidemics and other infectious outbreaks as well as behaviour-related risk factors can also increase mortality and interfere with the cold. In other terms, it is difficult to identify how much of the risk is connected to cold temperatures when dealing with winter ailments.
Also, even though climate models show a pattern of warming the climate is expected to become more variable within the next few decades, and the occurrence of major cold spells cannot be excluded.
Together with Météo-France the French Institute for Public Health Surveillance monitors the health impact of cold spells on a daily basis using its syndromic surveillance system SurSaUD®. In cases of bad weather forecasts or any observed health impact the health authorities are informed so they can issue suitable communication on what to do. However, long-term preventive measures such as fighting against fuel poverty are recognized by many countries as being the most efficient measures.
What does a newborn's future depend on? Answering this question requires taking into account all the elements of the environment likely to interfere with a child's development: family, social, economic, school, relationship and health factors.
In the late 1990s several public institutions and governmental agencies identified the need to carry out longitudinal studies in France, in particular to follow up children's future, and had started to develop a project along those lines. At the same time, the new National Environmental Health Plan (PNSE) was recommending the implementation of a cohort-type epidemiological study of children in order to better understand environmental and society determinants on health.
The project aimed at setting up a French cohort of 20,000 children was therefore initiated to meet those needs. Children are monitored from birth into adulthood in a multidisciplinary approach with several objectives: motor and cognitive development, education, family and social environment, etc. The cohort was called ELFE (from the French initials meaning Longitudinal Study of Children): https://www.elfe-france.fr/.
Health impacts caused by climate changes
Adapting to climate change – i.e. measures taken to deal with expected changes and limit potential damage - is now considered a public health priority. There is a broader range of potential impacts on health caused by climate changes: emergence or re-emergence of infectious diseases, extreme events becoming more frequent and more intense, significant changes to the environment, water quality, air quality, etc.
The French Institute for Public Health Surveillance strives to identify major risks for France and to suggest possible types of adaptive measures for surveillance and research. Although most risks are currently being monitored from an environmental and health point of view and do not require the development of new systems, climate changes pose new questions in terms of surveillance.
Health consequences of the AZF – Toulouse disaster
On Friday, 21 September 2001 at 10:17 a.m. an explosion occurred in the “AZF” factory near Toulouse. The violent force of the blast, equivalent to an earthquake of approximately 3.4 on the Richter scale, resulted in the death of 30 people and caused several thousand casualties.
Due to the scale of the disaster the French Institute for Public Health Surveillance (InVS) set up an epidemiological monitoring mechanism in the following days to monitor health consequences; many scientific and institutional partners were involved.
The purpose of the mechanism was to very quickly identify the risks for the population due to chemicals released in the environment so as to take (and adapt if necessary) specific surveillance and prevention measures, to assess screening requirements and the health and care to be provided to the population in the short and medium term, and to assess the scale of physical, mental and social sequelae among affected populations in the short and medium term. Three series of crosscutting surveys were carried out among affected populations, particularly among children, the general population, workers and rescuers.
Furthermore, monitoring of a cohort of 3,000 voluntary workers and rescuers was set up in order to assess the health, social and occupational consequences over a period of five years.
Heat and health
The heat wave of August 2003 resulted in an excess mortality of nearly 15,000 deaths, serving as a stark reminder of how vulnerable societies are to extreme climatic events.
As early as 2004 the French Institute for Public Health Surveillance set up several studies to improve knowledge on heat waves and to guide prevention. In cooperation with Météo-France it also implemented a Heat Wave and Health Alert System (Sacs) that is integrated in the National Heat Wave Plan (PNC), the purpose of which is to prevent heat from having major impacts on health.
Since 2003 the only intensive and sustained heat wave occurred in the summer of 2006. However, it resulted in fewer deaths than anticipated by models, and one can assume that the measures taken since the heat wave of August 2003 combined with the population’s awareness of heat-related risks helped to attenuate the expected impact. Surveillance and prevention efforts should continue and new avenues should be explored in order to deal with the increasing frequency of events caused by climate changes.
Incinerators and health
This topic focuses on the health impact of incinerating household waste and presents a comprehensive view of the work conducted by the InVS in this area. It includes reports on the diversity of work as well as the wealth of knowledge that has been produced and made available to the scientific community, decision-makers and the public. These studies and guides were produced by the InVS’s Department of Environmental Health and the Interregional Epidemiology Units, in cooperation with many public and private partners.
As lead plays no known physiological role in the human body its presence in the organism is always a sign of contamination. Lead absorbed through the digestive, respiratory or blood (mother to foetus) route finds its way into the bloodstream, soft tissues and especially bones (94%) in which it gradually accumulates and remains stored for a very long time (its half-life is greater than 10 years).
The level of lead in the bloodstream measured in venous blood is the indicator used to assess an uptake of lead. As a matter of fact, levels of lead reflect a balance at a certain point in time between a contamination process that might be ongoing, the amount of lead stored or released from the bones, and elimination (excretions, dander, sweat).
When the intoxication process has been stopped the level of lead decreases with a half-life of 20 to 30 days until a new balance is reached, the level of which depends on the amount of lead stored in the bones.
Levels of lead are expressed as µg/L or as µmol/L (1.0 µg/L = 0.004826 µmol/L and 1.0 µmol/L = 207.2 µg/L).
Cases of lead poisoning among children have been defined based on this indicator: a person under 18 whose level of lead exceeds the threshold of 100 µg/L constitutes a case of lead poisoning.
Infants are a particular target of intoxication because they ingest lead more frequently due to activities with their hands and mouth, and also because they have a high digestive absorption coefficient and their nervous system is still developing.
Natural and industrial disasters
Because they are sudden and unexpected natural and industrial disasters and their consequences are likely to have a major impact on human health. Whether natural or induced by humans, recent disasters have demonstrated the importance of adequately managing health impacts.
Impacts need to be evaluated and monitored in order to provide the various stakeholders in charge with reliable and objective information on the nature of the disaster, its importance and how it changes over time. Surveillance should start as quickly as possible after the event and continue in the long run if necessary. By providing information on medical conditions, most vulnerable populations and risk factors, epidemiology helps to guide the implementation of management measures aimed at attenuating the health impact of extreme events. But the epidemiological response to disasters needs to be prepared in advance of the event.
This topic focuses on InVS’s activities in the field of epidemiological response and preparedness to industrial or natural disasters.
Pesticides included many substances used in combating pests: insecticides, fungicides, herbicides, etc. They are used in agriculture but also have many other uses, including road maintenance, municipal park maintenance or fighting against unwanted insects in one's home.
Because they are widely used, small quantities of these products, called residues, find their way into the environment and into food. Though the effects of acute exposure are relatively well known those involving chronic exposure at small doses raise many questions.
After an introduction on the use of such substances in France and a presentation of the pesticide program at the French Institute for Public Health Surveillance (InVS) the four major sections of this topic are presented: a summary of current knowledge of the effects of pesticides on health, a description of the work on the general population's exposure to pesticides, occupational exposure, and risk assessments carried out in specific regional situations.
Polluted soils and health
This topic presents the activities of the French Institute for Public Health Surveillance (InVS) in the area of polluted soils and health. It includes a general introduction describing the issue, then presents various reports, documents and tools used by field epidemiologists as well as the studies that have been carried out. It also includes links to the websites of our main partners that provide further information and/or add to the matters addressed.
Polychlorinated biphenyls or PCBs
Polychlorinated biphenyls or PCBs are chemical compounds that are potentially dangerous to humans in the long run. They have been banned in France since 1987. These chlorinated derivatives are persistent in the environment and can accumulate in the food chain, in particular in some species of fish found in French rivers. Have people eating freshwater fish been more exposed to PCBs than the general population? To answer this question the Ministry in charge of Health funded a nationwide study known as an “uptake study”, coordinated by the French Food Safety Agency in cooperation with the French Institute for Public Health Surveillance. The study began in March 2009 and will help to define how often such fish can be consumed without presenting any danger to humans, depending on species of fish and target populations.
Water and health
This topic presents InVS activities in the area of surveillance of health risks related to water for human consumption. It includes a general introduction on water and health, topical pages describing work in progress, reports and documents produced, as well as a glossary containing useful technical terms for the pages included in this topic. It also provides links to the websites of our main partners and to other websites that provide more detailed information and add to the matters addressed.