Health Impact Assessment

Lead exposure has long been identified as a potential health threat for children. There is sufficient epidemiological evidence for justifying a causal relationship between exposure to lead and loss of IQ in children, and the relationship between blood lead level (BLL) and loss of IQ has been quantified in an exposure-response function (Lanphear et al., 2005). Although it is known that loss of IQ occurs at BLLs below the usual screening levels of 10µg/dL, only a few studies have estimated the health impact below this level. Preventive actions to reduce exposure to lead have been in place in some countries for many years. However, although it is known that blood lead levels decrease in a population as a result of such lead reduction actions, their relative impact in terms of health gain has not been studied.

At present, the health impact of lead in blood on the whole European population can not be estimated due to a lack of comparable data at the European level. A case specific health impact assessment was conducted in two different scenarios (with and without the existence of a lead exposure reduction programme), with the aim of evaluating the health gain accomplished by the implementation of lead exposure prevention actions and to illustrate the methodology of HIA with a practical example.

Blood lead level data of 3445 French children aged 1 to 6 years old from a national French survey conducted in 1991-1995 were used. The exposure-response function provided by Lanphear was used to estimate the potential health impact of BLL in terms of loss of IQ in the French population. According to Lanphear, the loss of IQ associated with the blood lead level categories of 24 to 100 µg /L, 100 to 200 µg /L and 200 to 300 µg/L was respectively 3.9; 1.9 and 1.1. Blood lead level data were modelled in order to estimate the blood lead levels expected in 2007 of children aged 5 to 7 years old. To account for the decrease in exposure and consequent lowering of blood lead levels due to implementation of lead exposure reduction programmes, reduction factors were applied in the model. The evaluation of the health impact was also performed without the application of such reduction factors, to represent the hypothetical scenario where no lead prevention actions were implemented.

The health impact assessment shows that almost 1 million (893,356) children in France are likely to suffer from a loss of IQ. Of these, 879 626 children would lose on average 3.9 IQ points, 13 393 children would lose 5.1 IQ points and 337 children would lose 6,2 IQ points (Table 1). Table 1 also shows the number of children affected in the two scenarios (with and without the implementation of lead exposure prevention actions) and the IQ points lost by these children in each of the BLL categories.

Table 1: Estimates of children affected in each blood lead level category and IQ points lost with and without lead exposure prevention actions.

This case study illustrates the health gain due to lead exposure prevention actions. Almost 2 million children (1 842 449) would have suffered from a loss of IQ if lead exposure prevention programmes had not been implemented. The health gain in terms of both number of children affected and total number of IQ points lost, has been approximately 50%. That is, 50% of the health impact of lead exposure has been already avoided by eliminating lead from gasoline and other exposure sources. Nevertheless, still almost 1 million (893 356) children in France will suffer from a loss of IQ. These results stress the importance of continuing efforts to reduce lead exposure through preventive actions, particularly in countries were these policies have not been yet fully implemented and where many children may still be affected by lead exposure. It also highlights the need to continue bio-monitoring blood lead levels in children, and to conduct further assessments of the health impact in terms of IQ and its potential consequences on society.

1. Lanphear BP, Hornung R, Khoury J, Yolton K, Baghurst P, Bellinger DC et al. Low-level environmental lead exposure and children's intellectual function: an international pooled analysis. Environ Health Perspect 2005; 113(7):894-899
2. World Health Organisation. Assessing the environmental burden of disease at national and local levels. Lead. Environmental Burden of Disease Series, No.2. Fewtrell L, Kaufmann R, Prüss-Üstun A. WHO. 2003
3. UNEP (1998). Global opportunities for reducing the use of leaded gasoline. UNEP, UNICEF, UNITAR, 1998. New York, United Nations Environment Programme (http://www.chem.unep.ch/pops/pdf/lead/context.pdf, accessed 2 September 2003).

Authors: María José Carroquino (ISCIII), Philippe Bretin (InVS), Odile Mekel (LOEGD)

Reviewers: Sarah Sierig (LOEGD), Alejandro Ramirez (ISCIII), Natalia Valero (ASPB), Manuel Gonzalez-Cabré (ASPB), Alain Le Tertre (InVS) and Sylvia Medina (InVS)

Long paper available on request, please e-mail to info@ecehbonn.euro.who.int

Guidelines for HIA on blood lead levels

Household use of solid fuels (such as dung, wood, agricultural residues, charcoal and coal) is likely to be the largest indoor source of air pollution in developing countries. Indoor exposure is a main determinant of the health of those living in the dwelling, including children.

Since the mid-1980s, epidemiological studies have been investigating the health impacts of exposure to indoor air pollution, mainly in countries in Africa, South East Asia and South America. The evidence available indicates that inhaling indoor smoke from combustion of solid fuels doubles the risk of pneumonia and other acute infections of the lower respiratory tract (ALRI) among children under five years of age.

Exposure to indoor air pollution from solid fuels used in cooking and heating has been barely studied in Europe and data are scarce. Therefore, HIA on this topic in European countries is not feasible.

Table 1: Health effects associated with exposure to indoor air pollution (supported by sufficient evidence) (1)

Table 2: Burden of disease for indoor air pollution in children 0-4 years old by EUR sub-region (2)

^a Defined the proportion of the outcome attributable to the exposure. Only the central estimate is reported

^b The Disability Adjusted Life Year or DALY is a health gap measure that extends the concept of potential years of life lost due to premature death (PYLL) to include equivalent years of ‘healthy’ life lost by virtue of being in states of poor health or disability. The DALY combines in one measure the time lived with disability and the time lost due to premature mortality. One DALY can be thought of as one lost year of ‘healthy’ life and the burden of disease as a measurement of the gap between current health status and an ideal situation where everyone lives into old age free of disease and disability (3).

* LE: lower estimate, CE: central estimate, UE: upper estimate

Table 3: Acute Lower Respiratory Infections deaths attributable to environmental factors for all countries and for the countries of the WHO European Region(4)

* Percentage indicates the proportion of all environmentally-caused deaths that are caused specifically by the environmental disease

In the case of the solid fuel indicator, the lack of valid epidemiologic data on the association between the exposure and the effect (exposure-response function) was a major constraint. We considered that the socio-economic status, the distribution of morbidities, and the baseline health status, among other factors, would not make it possible to generalize the available concentration-response functions from developing countries to the European scenario.

Therefore, it can be said that in order to know the real impact of the use of solid fuels on the health of the European population more research is critically needed in two dimensions: the prevalence of use of (or the prevalence of exposure to) solid fuels and the estimation of the risk between exposure and effect.

Due to these reasons it was decided not to carry out a Health Impact Assessment on the exposure of children to indoor air pollution from the use of solid fuels. However, in the literature, there is extensive material on the assessment of the Burden of Disease related to indoor air pollution from household use of solid fuels. A summarizing table of the burden of disease caused by the acute lower respiratory in the European Region is presented in Table 2.

It seems clear that exposure to indoor air pollution from combustion of solid fuels is related to health problems, especially in young children. While solid fuels are a dominant household energy source in developing countries, their use in developed countries it is not exactly known. If the estimates of exposure from the European sub-regions are accepted (Table 2), then we can conclude that for some countries or regions in Europe, in principle, exposure to indoor air pollution from solid fuels represents a public health problem, that accounts for approximately 340 818 DALYs (central estimate) in children from 0-4 years of age. A reduction of use and exposure to solid fuels in households would benefit the health of the population in countries of EUR B and EUR C. This reduction could ultimately result in a reduction of an important number of deaths caused, especially, by respiratory symptoms such as lower respiratory symptoms (Table 3).

• Burden of disease attributable to selected environmental factors and injuries among Europe's children and adolescents. Environmental Burden of Disease Series No.8. World Health Organization. (http://www.who.int/entity/quantifying_ehimpacts/publications/en/ebd8web.pdf)
• Comparative Quantification of Health Risks. Chapter 18: Indoor Air Pollution from Household use of solid fuels. World Health Organization. (http://who.int/publications/cra/chapters/volume2/1435-1494.pdf)
• Fuel for Life. Household energy and Health. World Health Organization. (http://www.who.int/entity/indoorair/publications/fuelforlife.pdf)
• ENHIS Fact Sheet on “Proportion of children living in homes using solid fuels”: Fact Sheet No. 3.6, Code RPG3_Hous_Ex3, May 2007. World Health Organization, 2007. (http://www.euro.who.int/Document/EHI/ENHIS_Factsheet_3_6.pdf)

1. World Health Organization. Fuel for Life: household energy and health (Written and Coordinated by Eva Rehfuess). WHO, Geneva 2006.
2. Valent F, Little D, Tamburlini G, Barbone F. Burden of disease attributable to selected environmental factors and injuries among Europe's children and adolescents. Geneva, World Health Organization, 2004 (WHO Environmental Burden of Disease Series, No. 8).
3. Murray CJL, Salomon JA, Mathers CD, Lopez AD (eds.) (2002). Summary measures of population health: concepts, ethics, measurement and applications. WHO, Geneva.
4. World Health Organization. Preventing disease through healthy environments. Towards an estimate of the environmental burden of disease. Prüss-Üstün A, Corvalan C. WHO, Geneva 2006.

Authors: Alejandro Ramirez (ISCIII)

Reviewers: Fiona Gore (WHO), Sophie Bonjour (WHO), Elena Boldo (ISCIII), Manuel Posada (ISCIII), Sylvia Medina (InVS).

Long paper available on request, please e-mail to info@ecehbonn.euro.who.int

HIA guidelines on solid fuel use (.pdf)

Epidemiological studies carried out on five continents have demonstrated that there are consistent associations between a range of adverse health outcomes and changes in the concentrations of PM10. Children are more vulnerable and susceptible than adults to the impact of air pollution because they are developing their lungs, their immune system is still immature, they spend more time outdoors and exercising, and they have an increased ventilation rate compared to adults(a). For asthmatic children, moreover, particulate matter can aggravate asthma (b).

An increase of 1.7% in premature mortality in children 0-4 years has been related with an increase of 10 µg/m3 in short-term exposure to PM10 (c). However, the amount of ill-health attributable to air pollution among European children is high (b)(c) due to the widespread nature of the exposure and the relatively high incidence of relevant health outcomes (i.e. respiratory problems) in the population.

Several Health Impact Assessments (HIA) have been carried out for atmospheric particulate pollution. In 2005, city reports on outdoor air pollution were carried out in 29 European cities (see http://www.apheis.net/CityReports2005/).These provide HIA for PM10 and ozone on mortality and morbidity indicators for each of the participating cities.

Focusing on children health effects is very relevant, because these deaths have a huge impact in years of life lost. According to CAFE-CBA, there were 700 infant deaths each year across 25 European countries from PM exposure (year 2000) (e). Apheis-3(d) associated a reduction of long-term exposure to PM10 to 20 µg/m3 with a decrease of more than 20 000 premature deaths for all-causes mortality in the general population (60 deaths /100 000 inhabitants).

In ENHIS (b), we have analysed the effects of PM10 on postneonatal mortality, on hospital respiratory admissions (0-14 years), and on cough and lower respiratory symptoms (5-17 years). A reduction of PM10 levels to 20 µg/m3 was associated with a decrease of 56 premature deaths for total postneonatal mortality (14 deaths/100 000 inhabitants). Regarding morbidity, a reduction of short-term exposure to PM10 to 20 µg/m3 was associated with a decrease of 7% for cough and lower respiratory symptoms, and of 2% for hospital respiratory admissions in children <15 years.

The main obstacle to creating a more complete picture of the health impacts of outdoor air pollution in Europe remains the availability of reliable routine morbidity data.

In ENHIS-2, the HIAir software and the corresponding guidelines (f) have been developed to allow online HIA calculations for urban air pollution. For the time being, the tool provides the number of health events that could potentially be prevented (or the gain in life expectancy) from an exposure to urban air pollution in a specific population. This enables evaluating different policy scenarios for reducing air-pollution levels, and can help to assess new strategies to reduce air pollution levels.

A HIA case-study using total population has been performed following HIAir guidelines.

The number of PM10 long-term attributable deaths in the city of Prague has been calculated with the HIAir software using data from European databases (see table 1).

The following example illustrates HIAir calculations for long-term attributable deaths at the city level and intercity comparative figures.

Table 1: PM10 long-term attributable deaths in the city of Prague. Scenario: PM10 level drops from 33.6 to 20 µg/m3

In 2004 the PM₁₀ annual mean in Prague was 33.6 µg/m3, with data available for 346 days. This assessment has estimated that, all other conditions being equal, between 400 and 900 "premature" deaths could potentially be prevented annually if long-term exposure to outdoor concentrations of PM₁₀ in this city could be reduced to 20 µg/m3. In other words, we could say the proportion of all-causes mortality attributable to a reduction to 20 µg/m3 would be 5.9 % of the total mortality in Prague.

Table 2: PM10 long-term attributable deaths. Comparison among Prague, Paris and Bonn.

Figure 1. PM10 long-term health impact on total mortality in Prague, Paris and Bonn. Reductions to 20 µg/m3. Number of deaths per 100 000 inhabitants

This HIA includes the following cities: Prague, Paris, Bonn.

This assessment has estimated that, all other conditions being equal, between 500 and 1100 "premature" deaths could potentially be prevented annually if long-term exposure to outdoor concentrations of PM₁₀ in all the 3 cities could be reduced to 20 µg/m³. In other words, we could say that the proportion of all-causes mortality attributable to a reduction to 20 µg/m³ would be 7.6 % of the total mortality in the cities.

Baselines assumptions:

HIAir assumes a causal relationship between exposure to air pollution and the health outcome under consideration. The scientific basis for this relationship has been widely supported in the literature.

The concentration-response functions (CRF) currently implemented are considered to be linear, assuming that there is no threshold below which air pollution has no impact on health for the general population.

HIAir chooses a conservative approach to deal with the uncertainties when determining the number of cases attributable to air pollution. In this sense, among others, HIAir only uses CRFs or risk estimates that are well established.

Limitations:

Mortality excluding external causes has been estimated applying a correction factor for each country to the total number of deaths.

Data provided by European databases for population and mortality may not apply exactly identical area definitions.

1. WHO. The effects of air pollution on children’s health and development: a review of the evidence. Executive Summary 2004. Available in: http://www.euro.who.int/document/EEHC/execsum.pdf
2. ENHIS. Implementing Environment and Health Information System in Europe. Final Technical Report. WHO, Bonn. 2005
3. Valent F, Little D, Bertollini R, Nemer LE, Barbone F, Tamburlini G. Burden of disease attributable to selected environmental factors and injury among children and adolescents in Europe. Lancet. 2004 Jun 19;363(9426):2032-9.
4. APHEIS 3. Health Impact Assessment of Air Pollution and Comunication Strategy. Third Year Report 2002-2003. July 2004. Available in: http://www.apheis.net/vfbisnvsApheis.pdf
5. CAFE Programme. Clean Air For Europe (CAFE) Cost Benefit Analysis (CBA): Baseline Analysis 2000 to 2020. AEA Technology Environment, United Kingdom. 2005.
6. HIA guidelines on outdoor air pollution (.pdf)

1. ENHIS. Implementing Environment and Health Information System in Europe. Final Technical Report. WHO, Bonn. 2005 http://ec.europa.eu/health/ph_projects/2003/action1/docs/2003_1_28_frep_en.pdf
2. Fact sheet indicator: Exposure of children to air pollution (particulate matter) in outdoor air http://www.enhis.org/object_document/o4741n27382.html

Authors: Natalia Valero, Piedad Martin Olmedo, Alejandro Lopez Ruiz

Reviewers: Elena Boldo, Alain Le Tertre and Sylvia Medina

Long paper available on request, please e-mail to info@ecehbonn.euro.who.int

HIA guidelines on outdoor air pollution (.pdf)

• Indoor radon comes from ground soils or building materials and accumulates mainly in indoor atmosphere where we pass 90% of our lives.
• Epidemiological and experimental studies show that radon is a lung cancer carcinogen. An indoor exposure to 100 Bq/m3 during around 30 years can increase the probability of dying of a lung cancer by 16%.
• Based on estimates of indoor radon exposure of the European population, experts estimate that lifetime exposure to the indoor radon levels in Europe (mean of 59 Bq.m-3) is responsible of 9% of all lung cancer deaths.
• Since action to lower levels in buildings is possible and it is one of the main public health environmental problems, it is important that national authorities engage actions against radon based on solid scientific evidence. HIA applied to different action scenarios is one important tool to assure a sound public health policy.
• Unfortunately there is insufficient epidemiologic information to estimate the relationship between health risks and radon exposure during childhood. Consequently, HIA of childhood exposure is currently not available to support actions to reduce radon in buildings intended for children.
• It is therefore important to do further research on childhood exposure to radon in dwellings and schools and its health impacts during lifetime.

Figure 1. Estimated national annual arithmetic mean of dwelling radon levels

Source : Dubois G.(2005) An Overview of Radon Surveys in Europe. EUR 21892 EN, EC. 168p

Table 1: Health effects associated with exposure to indoor radon (support of evidence) (1)

Radon is an important public health problem. Everybody is exposed to radon in dwellings during his or her entire life.

Radon and lung cancer

Epidemiological studies on miners’ cohorts and case-control studies in general populations provide strong evidence of lung cancer carcinogenicity of dwelling exposure to radon. Furthermore they allow a reliable exposure-response estimate. Applying the exposure-response relation to lifetime exposure in Europe (mean exposure of 59 Bq/m3) allows estimating that about 9% of lung cancer deaths in Europe are attributable to exposure to radon in dwellings.

Radon and leukaemia

There is some evidence based on dosimetry suggesting that there could be a relationship between leukaemia and exposure to radon. However, no epidemiological reliable findings plead for the existence of this relationship. Even though some ecological studies suggest a possible relationship between the risk of leukaemia during childhood and exposure to radon during childhood, there is no strong evidence for the causality of such a correlation. Up to now results of the case-control studies don’t suggest such a relationship.

Children exposure-response functions

Assessing the impact of indoor radon exposure during childhood raises an important methodological problem. What exposure-response relationship should be used? There is a lack of available data to assess the health impact attributable to indoor radon exposure during childhood. Data on young miners (teenagers) exposed to radon in mines in China don’t stress any different relation of what has been observed during adulthood exposure. But there are no epidemiological studies that checked any potential relation between exposure during childhood and risk of lung cancer.Furthermore, to be really relevant, a risk assessment should take into account the variability and the evolution of future exposure to tobacco. Indeed, this factor interacts with radon and is a very strong determinant of lung cancer.

Conclusions

For reasons expressed above HIA on exposure to radon during childhood was considered not feasible for the time being.More epidemiological studies are necessary to assess the issue of childhood radon exposure effects (leukaemia during childhood or lung cancer during adulthood). Applying the BEIRVI exposure response functions to children´s exposure at school in a cost–effectiveness study, the Quebec Public Health institute retained the action on radon in schools and buildings for children as one of the most cost-effective, not without methodological difficulties.There is a need for expert review on the specific topic of extrapolation of exposure response functions from adult exposure to children exposure. We strongly stress the need for a specific focus on the health effects of childhood exposure by the expert committees such as the International Radon Project coordinated by the WHO Geneva http://www.who.int/ionizing_radiation/env/radon/en/index.html, or the European Community research project ALPHARISK.

General: http://www.who.int/ionizing_radiation/env/radon/en/index.html.

Radon and Leukemia

Evrard AS, Hemon D, Billon S, Laurier D, Jougla E, Tirmarche M, Clavel J. Childhood leukemia incidence and exposure to indoor radon, terrestrial and cosmic gamma radiation.

Health Phys. 2006 Jun;90(6):569-79.

Evrard AS, Hemon D, Billon S, Laurier D, Jougla E, Tirmarche M, Clavel J. Ecological association between indoor radon concentration and childhood leukaemia incidence in France, 1990-1998. Eur J Cancer Prev. 2005 Apr;14(2):147-57.

Laurier D, Valenty M, Tirmarche M. Radon exposure and the risk of leukemia: a review of epidemiological studies. Health Phys. 2001 Sep;81(3):272-88. Review.

Radon and lung cancer

National Research Concil. Health Effects of Exposure to Radon: BEIR VI. 1999.

Darby S, Hill D, Auvinen A, Barros-Dios JM, Baysson H, Bochicchio F, Deo H, Falk R, Forastiere F, Hakama M, Heid I, Kreienbrock L, Kreuzer M, Lagarde F, Makelainen I, Muirhead C, Oberaigner W, Pershagen G, Ruano-Ravina A, Ruosteenoja E, Rosario AS, Tirmarche M, Tomasek L, Whitley E, Wichmann HE, Doll R. Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies. BMJ. 2005

Dessau JC, Gagnon F, Lévesque B, Prévost C, Leclerc J-M, Belles-Isles JC. 2005. Le radon au Québec - Évaluation du risque à la santé et analyse critique des stratégies d’intervention. INSPQ, 118 p. + annexes.

Radon exposure data (Source JRC)

Report of the United Nations Scientific Committee on the Effects of Atomic Radiation. New York, United Nations, 2000 Sources and Effects of Ionizing Radiation. UNSCEAR 2000 Report to the General Assembly, with Scientific Annexes. Vol I: Sources. New York: United Nations, 2000. (http://daccessdds.un.org/doc/UNDOC/GEN/N00/587/20/IMG/N0058720.pdf?OpenElement, accessed 4 April 2007).

Dubois G. An overview of radon surveys in Europe. Luxembourg, Office for Official Publications of the European Communities, 2005 (EUR 21892 EN).

WHO ENHIS factsheet indicator: exposure to radon in European countries: ”Radon levels in dwellings”. http://www.enhis.org/object_document/o4723n27388.html.

Authors: Philippe Pirard, InVS.

Reviewers: Hajo Zeeb (IMBEI), Olivier Catelinois (InVS), Alejandro Ramirez (ISCIII), Elena Boldo (ISCIII), Sylvia Medina (InVS).

Long paper available on request, please e-mail to info@ecehbonn.euro.who.int

HIA guidelines on radon (.pdf)

Environmental noise is expected to become one of the major environmental health issues in Europe. In 1998 it was estimated that 32 % of the European population was exposed to noise levels over 55 dB(A) (LDN) and 13 % to noise levels over 65 dB(A) (LDN). At present the health impact of road traffic noise on the whole European population can not be estimated due to the lack of current exposure data at European level.

A Health Impact Assessment (HIA) case study in children (0-14 yrs) on health effects induced by road traffic noise was conducted in two German cities in North Rhine-Westphalia, one small town (city A), the other a larger city in a highly compressed area (city B). 17 %– 34 % of children in these cities are estimated to be exposed to noise levels of more than 60 dB(A) during the day (see Figure 1). At night, 21 % – 34 % of children are estimated to be exposed to noise levels of more than 50 dB(A).

Figure 1. Traffic noise exposed children (0-14 years) in two cities in NRW during daytime

By HIA analyses we estimated the fraction of highly annoyed and highly sleep disturbed children per 1000 children in both North Rhine-Westphalian cities, for: i) the current situation; ii) for scenario 1 (assuming that noise exposure does not exceed 60 dB(A) during daytime and 50 dB(A) at night); iii) and for scenario 2 (assuming noise levels L(DN) decreased by 5 dB(A)).

In the current scenario the estimated proportion of highly annoyed children due to road traffic noise is 5.4 % in the small city (city A) and 10.1 % in the urban city (city B). The estimated proportion of children that is highly sleep disturbed due to road traffic noise is 4.6 % in city A and 5.2 % in the city B.

Compared to the current scenario, scenario 1 shows that the proportion of highly annoyed children could be reduced by about 10 per 1000 (city A) and 30 per 1000 (city B) (Figure 2). In scenario 2 the proportion of highly annoyed children could be reduced by about 20 per 1000 (city A) and 39 per 1000 (city B), compared to the current situation (Figure 2).

Figure 2. Estimated fraction of highly annoyed children (per 1000) in two North Rhine-Westphalian cities, for the current situation, for scenario 1 (assuming that noise exposure does not exceed 60 dB(A) during daytime and 50 dB(A) at night), and for scenario 2 (assuming noise levels L(DN) decreased by 5 dB(A))

The proportion of highly annoyed or highly sleep disturbed children (in %) which could be avoided by the exposure reduction measure was calculated (Table 1) This can be interpreted as a health gain. The health gain for annoyance would vary between 19 % and 38 % for both scenarios and cities. The proportion of avoided highly sleep disturbed children would vary between 19 % and 28 % for both cities and scenarios (Table 1).

Table 1 Proportion of highly annoyed and highly sleep disturbed children (current situation, scenario 1, and scenario 2) in absolute numbers for both cities. For scenario 1 and 2, the health gain (in percent) is presented.

Compared to the current situation, scenario 1 and scenario 2 both show a clear decrease of the negative health outcomes in both cities. Therefore preventive actions to reduce traffic noise exposure as suggested in the END (Environmental Health Directive) should be strengthened in Europe. It was also discussed to what extent uncertainties of the applied method might result in an over- or underestimation of the health impacts.

• Fact sheet indicator Children living in the proximity of heavily trafficked roads
• WHO/Europe: noise and health: http://www.euro.who.int/Noise
• EU Directive 2002/49/EC - Environmental Noise Directive (END) : http://eur-lex.europa.eu/pri/en/oj/dat/2002/l_189/l_18920020718en00120025.pdf

Authors: Odile Mekel (LOEGD), Sarah Sierig (LOEGD) and Thomas Claßen (LOEGD)

Reviewers: Elise van Kempen (RIVM), Danny Houthuijs (RIVM), Sylvia Medina (InVS)

Long paper available on request, please e-mail to info@ecehbonn.euro.who.int

HIA guidelines on road traffic noise (.pdf)

Excessive indoor dampness is a public health problem in European countries. Dampness induces namely the growth of moulds, dust mites and various microbial agents which in turn may affect health. Damp and moulds are important risk factors for the respiratory diseases and effects on immune systems. For dampness itself, the strongest evidence exists for the association with aggravation and development of asthma, and also for wheeze and cough prevalence. According to the WHO expert estimation, about 13% of asthma of European children is caused by dampness in homes, based on an estimated exposure prevalence of 15% (1).

In European countries the health requirements within housing regulations are often vaguely defined, and are frequently not dealing with dampness issues at all. The responsibility to avoid or reduce damp problems is largely left to the occupants.

There is limited information on households suffering from dampness problems in European countries, and for HIA purposes this information is unsuitable. Therefore, it was not feasible to conduct HIA on damp induced health effects on children at the European scale. Moreover, data on health effects have not been reported in an inter-country comparable form. Until employing a standard methodology for exposure assessment across the European Region, making between-country comparisons based on Eurostat data or specific survey data is problematic.

A case study from the Czech Republic tested an approach of using data from a large cross-sectional survey focused on the health outcomes resulting from inadequate housing, based on a spatially representative sample of the child population and providing both exposure and health data needed for HIA. The results of the case study are not strictly comparable to those from other studies, due to different study designs and exposure definitions, as well as limitations related to self-reporting of exposure used in the majority of studies. The results may serve as information for the national policy makers who wish to estimate the relevance of the damp household problems and the need for housing stock reconditioning.

According to the estimation, about 4% of asthma cases in children could be a consequence of the reported exposure to damp/moulds at home. Extrapolating these figures to the whole Czech child population in the relevant age group, about 3 080 asthma cases (range: 660 to 6 290) could be attributable to reported dampness/moulds at homes in the Czech Republic, which means about 220 (range: 50 to 440) cases per 100 000 children in this age group (see Tab. 1). Also, early exposure in the first years of child’s life is a high risk factor for later asthma development. Based on findings from 2001, avoiding this early exposure could later abate almost 10% of asthma cases in children, which represents 500 (range: 280 – 770) cases per 100 000 children.

Tab. 1 Estimated population attributable risk (PAR) and estimated number of asthma cases attributable to reported damp/moulds exposure at home in the Czech child population (5 – 17 years of age), ORs derived from the survey (2001)

*- asthma prevalence in the group of exposed children

⁺ - based on OR central estimates and 95% CI intervals

The results of the repeated study in 2006 confirmed the finding on early exposure. Since the association between reported recent exposure and asthma was found inferior in the second study period, additional calculations were made using the exposure-response function interval based on the literature review: OR 1.4 – 2.2 (2). This enables assessing the time trend for both study periods on the number of asthma cases attributable to exposure to dampness/moulds. The attributable risks (PARs) are essentially similar for both study periods as a consequence of similar reported exposure prevalence. The number of attributable cases increased in the second study period compared to the first period as the asthma prevalence rate increased in 2006 (see Tab. 2).

Tab. 2 Estimated number of asthma cases in children attributable to reported damp/moulds exposure in both study periods, used OR interval 1.40 – 2.20

Even if this cross-sectional study could not provide scientifically accurate data for exact assessment and many limitations are involved, the estimated amount of avoidable cases of asthma indicates the potential benefits of reducing the number of households with damp problems in terms of children’s health impact. The results support a recommendation to prevent dampness and moulds occurrence in homes, particularly in children’s rooms, by targeted preventive policies, and to take remedial actions where these problems occur.

A standardized methodology for exposure assessment across the European Region is needed, otherwise making between-country comparisons as well as performing HIA will remain problematic. Household interview surveys (HIS) can be used to produce estimates of the number of dwellings/children affected by damp/moulds, e.g. by refining the dampness evaluation module or by combining the HIS survey with the LARES inspections methodology. In order to quantify the health-related effects, additional information should be collected from national surveys based also on standardised methodology (3).

• Prevalence of asthma and allergies in children: http://www.euro.who.int/Document/EHI/ENHIS_Factsheet_3_1.pdf
• WHO web page on Housing and Health: http://www.euro.who.int/Housing

1. WHO second technical meeting on quantifying disease from inadequate housing, Bonn, November 2006.
2. Bornehag CG, Blomquist G, Gyntelberg F, Järvholm B, Malmberg P, Nordvall L, Nielsen A, Pershagen G, Sundell J. Dampness in buildings and health. Nordic interdisciplinary review on the scientific evidence on associations between exposure to “dampness” in buildings and health effects (NORDDAMP). Indoor Air 2001;11: pp 72-86
3. ENHIS2 Fact Sheet 3.5. RPG3_Hous_Ex1: Children living in homes with problems of damp, WHO Bonn, 2007, http://www.euro.who.int/Document/EHI/ENHIS_Factsheet_3_5.pdf

Authors: Vladimira Puklova, Jana Kratenova (SZU)

Reviewers: Ulla Haverinen (KTL), Elena Boldo (ISCIII), Odile Mekel (LOEGD), Sarah Sierig (LOEGD), Alejandro Ramirez (ISCIII), Natalia Valero (ASPB), Manuel Gonzalez-Cabré (ASPB), Alain Le Tertre (InVS) and Sylvia Medina (InVS)

Long paper available on request, please e-mail to info@ecehbonn.euro.who.int

Guidelines for HIA on dampness (.pdf)

Environmental tobacco smoke (ETS) is a serious health hazard. The smoking ban in public places is gaining momentum with increasing numbers of countries that have implemented complete smoking bans in public places. However, much less attention has been paid to protect children from ETS, mainly occurring in the home environment.

Indeed, despite the fact that ETS is one of the most important sources of harmful indoor air pollution, that no level of exposure is considered safe and that it is a serious health risk to children, many children are still exposed to this hazard at home.

Exposure can harm even before birth. ETS exposure in uterus and in infancy causes a wide range of effects the health (mortality and morbidity) of children. Parental smoking doubles the risk for Sudden Infant Death Syndrome (SIDS) and is causally associated with an increased incidence of asthma episodes.

An HIA was conducted to assess the potential health impact of ETS on European children. Considering the estimated current smoking prevalence for all adults (see Figure 1), 279 SIDS cases could be attributed to exposure to ETS at home (see Table 1). This represents around 21% of all SIDS cases in five million children younger than 1 year in 27 European countries. The findings also suggest that exposure to ETS can increase the number of asthma episodes by an average of 6% in children younger than 14 years.

The data on asthma prevalence is available for selected populations only, and demonstrates huge inter-regional variability. Also the number of attacks occurring in children with asthma is difficult to evaluate. Therefore it is impossible to estimate the absolute number of asthma attacks attributable to ETS exposure. To illustrate the magnitude of the problem, the following assumptions can be made for a city (population 100 000) with 20 000 children younger than 14 years, and with asthma prevalence around 3% (i.e. 600 children with asthma). If each child with asthma experiences 300 attacks per year, then the additional number of asthma attacks attributable to ETS exposure in this population would be 600*300*0.06= 10 800 attacks. This is a hypothetical projection but the figures are realistic.

Figure 1 Current smoking prevalence in adults by European country (%)

Source: http://data.euro.who.int/tobacco/

Table 1 Health Impact Assessment of ETS exposure for Sudden Infant Death Syndrome (SIDS) cases in 27 European countries

1. The study area included the folowing European countries: Austria, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, The former Yugoslav Republic of Macedonia, United Kingdom.

2. Eurostat databases (http://europa.eu.int/comm/eurostat)

In general, the numbers of SIDS are decreasing considerably over time, while asthma prevalence is rising in European children. In relation to ETS, the decreasing trends in national smoking prevalence for all adults as seen in 10 selected countries from 1995 to 2004 may have contributed to a 50% decrease in the percentage of SIDS (from 449 to 204 SIDS cases) (Figure 2), and to a much lesser percent decrease (1%) in asthma episodes (Figure 3).

Figure 2. Trends in the number of excess SIDS cases attributable to ETS exposure by country considering smoking prevalence for all adults in 10 European countries

Figure 3 Trends in the fraction (%) of asthma attributable to ETS exposure in children younger than 14y considering smoking prevalence for all adults in 10 European countries

In view of the considerable benefits on children’s health, measures to restrict smoking in indoor environments, especially at home, should be a major public health priority action. In fact, most European countries have been able to promote reductions in smoking prevalence. As public health officials, we consider that further reductions in ETS exposure have to be encouraged in European countries. Particularly, preventive policies should strongly promote smoke-free homes and cars.

• Fact sheet indicator: Exposure of children to Environmental Tobacco Smoke http://www.enhis.org/object_document/o4744n27382.html. Accessed 25 September 2007
• Fact sheet indicator: Policies to reduce the exposure of children to Environmental Tobacco Smoke http://www.enhis.org/object_document/o4727n27382.html Accessed 29 September 2007
• Fact sheet indicator : Prevalence of asthma and allergies in children http://www.enhis.org/object_document/o4735n27382.html Accessed 15 October 2007
• U.S. Department of Health and Human Services. "The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General”, 2006. http://www.surgeongeneral.gov/library/secondhandsmoke/ Accessed 15 January 2007
• WHO International Agency for Research on Cancer "Tobacco Smoke and Involuntary Smoking" IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 83, 2002. http://monographs.iarc.fr/ENG/Monographs/vol83/volume83.pdf Accessed 15 March 2007

Authors: Elena Boldo (ISCIII)

Reviewers: Sylvia Medina (InVS), Manuel Posada (ISCIII), Mattias Öberg (Karolinska Institute), Kristiina.Patja (KTL) Odile Mëckel (LOEDG), Sarah Sierig (LOEDG), Alejandro Ramirez (ISCIII), Natalia Valero (ASPB), Dafina Dalbokova, Michal Krzyzanowski.

Long paper available on request, please e-mail to info@ecehbonn.euro.who.int

Guidelines for HIA on ETS (.pdf)

Water utility managers and health or water authority officers are supposed to understand the meaning of common data on drinking water quality in terms of health risks. Then they are capable to adapt appropriate strategies to respond to results monitored. Unfortunately, it was shown by recent studies that often even water professionals, public health and environmental specialists do not draw appropriate conclusions from available monitoring data. This paper describes examples of conclusions and experiences which can be derived from routinely collected monitoring data on water quality and health.

It also discusses the conditions when quantitative or only qualitative health impact assessments are applicable. This includes principles for the definition of limit values as well as possible lessons learnt from non-compliance with drinking water regulations and deviant meaning and purpose of drinking water parameters. In case numerical data on water quality is available, the basics of quantitative health risk assessment are outlined, e.g. how to calculate safe limit values for derogation or accident cases or how to assess the carcinogenic potency. Finally discussed are potential lessons derived from data on water-borne outbreaks.

Author: František Kožíšek (SZU)

Reviewers: Elena Boldo (ISCIII) and Sylvia Medina (InVS)

Long paper available on request, please e-mail to info@ecehbonn.euro.who.int

Guidelines for HIA on drinking water pollution (.pdf)