Gennemgang af miljøreguleringen med fokus på sundhedsaspekterne

Gennemgang af miljøreguleringen med fokus på sundhedsaspekterne

Summary and conclusions

The World Health Organization (WHO) defines health broadly, as a state of complete physical, social and mental well-being, and not merely the absence of disease or infirmity.

Health is affected by many factors, including such lifestyle factors, like tobacco, alcohol, food, exercise and overweight, and by chemical, physical or microbiologi-cal factors in the environment, in food, in the home and at the place of work.

This report describes the environmental factors that affect human health. Factors which are found in the air, soil, drinking water, bathing water, swimming pools, chemical substances and products, waste, wastewater and noise.

The report is a technical overview report. It presents the main problems relating to health, regulation of the field, and a short evaluation of each field.

Due to the complex exposure situations and to the difficulty of isolating exposure from one single factor, it can be difficult to estimate the actual impact on human health from single factors in the environment. Historically, one of the chief purposes of Danish environmental regulation has been to protect the population against adverse effects from exposure to environmental factors. One example is the case of waste and wastewater regulation. Efforts to protect the environment and public health are therefore highly integrated.

The general assessment is that there is a high level of protection, especially in relation to soil, water, waste and wastewater. The level of protection in national regulation of environmental factors is generally based on the precautionary principle, e.g. risk assessments, establishment of quality criteria, and application of safety factors and consideration for sensitive target groups when designing protection levels. The precautionary principle is an important political principle, which is applied where harmful effects are suspected and the scientific evidence is insufficient.

The precautionary principle is an important political principle in EU and in Denmark. Denmark finds it important to use to the widest possible extent in areas regulated at EU level, e.g. chemicals and pesticides.

Chapter 1 describes and defines a model for environmental factors and human exposure. The model describes life cycles of environmental factors, from emission at the source to human exposure and health effects.

Environmental factors are physical, chemical or biological components in the environment, which may affect human health and well being. They include micro-organisms, noise, airborne particles, pesticides, metals and radiation.

A description is given of the primary sources of generation or emission of environmental factors in different sectors – for example, industry, agriculture and waste management. Products and waste are carriers of environmental factors that eventually end up in environmental media (air, soil and water).

Humans may be exposed to environmental factors through contact with products and waste or through contaminated environmental media. Exposure depends on the occurrence and magnitude of the factor and on the presence of humans.

Chapter 2 gives an outline of environmental legislation in Denmark, focussing on the relation between environmental factors and health and on players and instruments.

Environmental law in Denmark covers most of the regulation of environmental factors relating to health and is to a great extent a subset of what is normally understood as environmental regulation. The institutional set-up is briefly presented, describing the interface with other areas, such as food or health and safety at work.

Chapter 3 describes environmental factors in the air. The overall objective is to achieve an air quality that does not have adverse effects on public health. However, due to the present levels of some air pollutants, a more realistic objective today is to further reduce the level of air pollution in order to minimise any harmful impacts on public health. New and planned EU air quality directives and related vehicle, fuel and industrial directives will establish consistent limit values for pollutants, and vehicle and large-industry requirements in all EU Member States. The directives will mean continued reduction of the transboundary pollution that affects health in Denmark.

In the past decade the level of most primary air pollutants affecting health has been reduced, mainly as a result of improvements in energy production and the fact that catalytic converters have been required in new cars since 1990. However, the reduction of NO₂ levels in urban areas has been modest, due largely to the fact that the amount of NO₂ in the air is determined by the amount of ozone in the air. The ozone level in Denmark is determined by the overland transport of ozone.

For several pollutants, e.g. particles, ozone and such carcinogens as benzene and benzo(a)pyrene, it has not been possible to identify lower health thresholds. Based on international studies, the observed levels of fine particles (PM_2.5) in Denmark could imply increased premature mortality and illness among sensitive groups (persons with respiratory and heart diseases), which constitute a large proportion of the population. The level of these health impacts is only roughly estimated in Den-mark, because research in these problems has been limited and there has been no regular monitoring of fine particles.

In recent Danish studies the average daily human exposure to dioxins is estimated to exceed the WHO guideline for tolerable daily intake, but it is not clear to what extent such exposure levels contribute to effects in the Danish population.

Chapter 4 focuses on environmental factors in soil. The aim of health-based regulation of soil contamination in Denmark is to avoid any harmful impact on public health. To achieve this aim, risk assessment procedures and health based soil quality criteria have been developed, based on the precautionary principle. The soil quality criteria are directed towards the protection of children, the most vulnerable group.

A large part of soil contamination originates from earlier or present activities, e.g. industrial and agricultural activities and storage of liquid fuels. Other sources are deposition of airborne pollution. Among the most important contaminants are heavy metals, oil products and fuel additives, polyaromatic hydrocarbons, chlorinated solvents and pesticides. In Denmark, the most significant human exposure routes are considered to be ingestion of, or skin contact with, contaminated soil, ingestion of drinking water and evaporation of contaminants to indoor air.

Great efforts are invested in mapping contaminated sites and/or preventing exposure when contamination is found. Mapping and prevention is highly prioritised, first and foremost by the most sensitive land-uses, e.g. residential use, childcare institutions, public playgrounds and sites where groundwater is threatened.

Chapter 5 deals with environmental factors in drinking water. The objective of drinking water regulation in Denmark is to ensure that the drinking water is based on unpolluted groundwater and is tasty, clear and odourless. Consumers must be able to drink it without worrying about possible contamination, and protection of groundwater resources therefore has very high priority. Groundwater quality criteria are generally the same or slightly higher than those for drinking water, which basically follow the EU Directive on drinking water.

Environmental factors in drinking water often originate from soil contaminants that percolate into the groundwater aquifers. Other sources are extraction-induced contamination, e.g. influx of salt or release of nickel from geological strata caused by lowering of the groundwater table. Lastly, contamination may be introduced in the supply network, especially in the form of microbial growth or as accidental inflow of wastewater.

Health impacts caused by consumption of drinking water are rare in Denmark, and the objectives of regulation are generally achieved. However, health impacts do occur, primarily as disease caused by microbial contamination in the supply network. Health impacts from chemical compounds in drinking water are only observed in a very few cases in the form of nickel allergy or met-hemoglobinenia (reduction of the oxygen-transporting properties of haemoglobin, especially children) caused by nitrates.

A key element of the Danish Water Supply Act is the designation of drinking water areas that are particularly exposed to contaminants. The areas identified must be assessed through detailed mapping of land use, pollution threats and geological protection of the groundwater resources. The assessment is intended to result in an action plan describing possible needs for restrictions on land use.

An important characteristic of the threat to drinking water resources is the delay between the occurrence of contamination and the presence of contaminants in the groundwater. Many contaminants are probably on the way down to the groundwa-ter and cannot be stopped by new regulation. A large number of drinking water borings are no longer used because of groundwater contamination from point sources or diffuse sources, and this development is expected to continue. Regulation today will in most cases only yield results after many years.

Today, we do not know all the substances likely to pollute our groundwater resources. The great challenge of the future is to identify substances that are not yet recognised as potential health factors. The precautionary principle must ensure that groundwater is protected against chemicals about which we have only limited knowledge.

Chapter 6 deals with environmental factors in bathing water. The objective is to prevent bathers from becoming ill when going for a swim in water designated as bathing water.

Environmental factors in bathing water in Denmark primarily originate in wastewa-ter. The primary impact comes from overflow of untreated wastewater during heavy rain, but also from run-off from rural areas and from scattered rural settlements that are not connected to a wastewater treatment plant. Other sources may be people using the water for recreational purposes, birds and other fauna, micro-organisms and, to a lesser extent, also industrial processes and farming. Micro-organisms of concern are blue-green algae. Algae secrete toxins, but only in rare cases are the concentrations high enough to affect humans. In Denmark, there have been no fatal cases of poisoning by algae and no reported epidemics.

There have been no recognised cases of adverse health impacts from contaminated bathing water for many years, and within the last decade, the impact of wastewater on the aquatic environment has been further reduced. However, some bathing waters are still affected by wastewater.

The instruments used to achieve the objectives include regional and local planning, design of sewerage systems, discharge requirements, monitoring of bathing water quality, and – if the water quality is unacceptable - occasional bathing bans. The microbial quality of bathing waters is monitored, but it is open for discussion whether the traditional bacterial indicators (faecal coliforms) accurately reflect the quality of the water, e.g. the occurrence of more resistant micro-organisms such as viruses and protozoa. Therefore, the Danish monitoring programmes are now being revised with respect to indicator parameters, monitoring frequency and the reaction time between monitoring results and possible regulatory action.

Chapter 7 deals with environmental factors relating to swimming pools, spas and similar recreational aquatic environments. The health objective is to ensure that the facilities are operated safely in order to avoid adverse health effects and illness in the people using them. The objective is to ensure that the quality of water in swimming pools does not impair health and that the water is sufficiently disinfected to prevent the occurrence of pathogenic micro-organisms.

Environmental factors in recreational waters include faecal and non-faecal micro-organisms originating from swimmers or contaminated water, from chemicals and by-products related to water treatment, and chemicals contributed by the swimmers, e.g. soap residues, cosmetics, suntan oil, sweat and urine.

Human exposure occurs through ingestion of water or inhalation of aerosols and gases like chloroform during swimming and/or through breaks in the protective skin barrier. Acute effects, such as skin and respiratory irritation resulting from exposure to disinfectants and by-products in the water and in the breathing zone, are described, but the resulting impact on human health is not known. This is also the case with possible long-term effects from exposure to chemicals. Many of the outbreaks of illness related to swimming pools and other recreational water environments have occurred because of inadequate or no disinfection.

The Danish protection level is considered high, but present regulation is under revision in order to take into account the latest knowledge and technological progress.

Chapter 8 focuses on chemical substances in products. The main objective of chemical regulation is to prevent health hazards and to protect humans against adverse health effects from exposure to chemicals. A second objective is to promote the use of less harmful chemicals through cleaner technologies and products.

Exposure to chemicals largely depends on the use situations. Different patterns are typically seen in relation to occupational exposure to industrial chemicals and exposure of consumers to for example household products and chemicals released from toys, clothes and building materials.

It is estimated that about 30,000-50,000 chemical substances are on the market in Europe. Relatively little is known about the actual health effects associated with the use of chemicals. In the case of acute effects, such as toxic, harmful, irritant and corrosive effects, it is usually easy to establish a relationship between the exposure to a given chemical and the actual effect because the response follows immediately after the exposure. When it comes to long-term effects like cancer, mutagenicity and reproductive toxicity, it is more difficult to establish firm scientific evidence of effects in humans.

Key elements in chemical regulation include risk assessment procedures, premar-keting authorisation schemes, classification and labelling of chemical substances and products, and restrictions on the use of chemicals. Other instruments are voluntary agreements, green procurement guidelines, information and campaigns, taxes and fees, and subsidies.

Regulation of chemical substances is based on existing knowledge and on the pre-cautionary principle because we do not have sufficient knowledge about the health effects of a large number of substances. Another important aspect is the protection of risk groups, with special focus on pregnant women and children, who are either more susceptible to chemical exposure or, in some cases, more exposed.

Major challenges in chemical regulation are the procurement of information about the many substances that have not been sufficiently investigated and identification of problematical substances by means, for example, of computerised QSAR modelling for prediction of inherent substance properties.

Chapter 9 gives an account of the environmental factors in waste. One of the overall health objectives of waste regulation is to avoid any harmful impacts on public health. From the start of waste management history in Denmark more than a century ago, protection of public health has been an integral element of waste regulation. Human contact with waste is limited, but the population may still be indirectly exposed to emissions resulting from handling of waste.

The objective is to identify and separate the problematical waste fractions in order to reduce the emission of substances that may have an adverse impact on human health and the environment. The instruments used are both detailed regulation and economic instruments like taxes and waste fees. Regulations are in place covering separation of special waste fractions and hazardous waste in order to improve the possibilities for recycling. The general principle of waste separation as close to the source as possible is also crucial to the possibilities for recycling and reuse. Another vital health protection measure in the Danish waste management system is the classification of hazardous waste.

Chapter 10 presents the environmental factors in wastewater. The overall health objective of wastewater regulation is to avoid any harmful effects on public health, whether directly through discharges to surface water or soil or indirectly through leaching to groundwater, inflow to drinking water installations or application to farmland.

Existing wastewater regulation in Denmark has generally succeeded in limiting public exposure to wastewater. Only a few cases of drinking water contamination with wastewater have been recorded in Denmark, and they were caused by inflow of wastewater into the water supply network. However, they affected a number of persons.

The primary health-related concern in connection with wastewater is exposure through bathing water. Although there has been a substantial reduction in wastewa-ter impacts on the aquatic environment in the last decade, some bathing waters are still affected by wastewater, mainly from overflow of untreated wastewater during heavy rain, but also by run-off from rural areas and from scattered rural settlements that are not connected to wastewater treatment plants. However, no diseases or other cases of adverse health impacts from contaminated bathing water have been recorded for many years.

99% of all wastewater going into sewers is treated in a wastewater treatment plant. In May 1997, the Danish Folketing adopted an action plan for improved wastewa-ter treatment for scattered buildings in the countryside. The action plan includes connection to the public sewerage system, local sand infiltration plants or small wastewater treatment plants. The action plan will help to improve general water quality in rivers, lakes and coastal waters and thereby also help to improve the quality of bathing water in Denmark.

Health concerns relating to chemical contaminants in wastewater focus on heavy metals and man-made chemical substances and, particularly, the risk of accumulation in fish in recipients and the risk of transference to agricultural crops when sludge is used as a fertiliser in farming. Attempts have been made for many years to recycle the sludge from wastewater treatment plants as a fertiliser on farmland. However, owing to difficulties in reaching the required criteria for sludge the farmers’ reluctance to receive sludge for fertilising purposes, some of the sludge is deposited in landfills or incinerated.

Chapter 11 focuses on noise – one of the environmental factors that affects most people in Denmark. Environmental noise in Denmark is normally so low that it is not likely to cause serious damages to humans but can be annoying and have adverse side effects.

Current guidelines and limit values reflect a compromise between high quality of life and socio-economic considerations (technical, economic and community aspects), accepting that a small proportion of the public (typically the 10% most sensitive citizens) might still feel highly annoyed. Recent environmental noise mapping shows that between a half and one million of the Danish population suffers from high noise impacts. Traffic noise is the main source, and the majority of people suffering from traffic noise live in residential areas in big cities. Much effort has gone into mapping traffic noise and evaluating possible action to reduce the number of people affected by it.

The only way to control and reduce traffic noise is well-planned land use and infrastructure. For new public infrastructure, noise aspects must be considered as part of the Environmental Impact Assessment procedure. For new enterprises and public infrastructure, the noise polluter bears all costs relating to planning and implementation of the noise abatement measures required. Airports must obtain an environmental approval before starting operations.

The European Union will soon present a new Directive on Assessment and Management of Environmental Noise, dealing with noise mapping, action plans, common indicators and information to the public. The Directive is expected to increase focus on noise and on the need for measures to control and reduce noise impacts.