Environment threatens children’s health [Archives:2006/909/Health]

January 5 2006

Dr. Saleh Al-Habshi
Master of Public Health

Children today live in an environment vastly different from that of a few generations ago. New challenges include increasing industrialization and globalization, rapid urban population growth, non-sustainable consumption of natural resources and increases in the trade and use of chemicals.

While economic development and improved hygiene and health care have led to a significant decrease in childhood morbidity and mortality in many parts of the world, new modern risks to children's health must now be added to basic environmental risks such as unsafe drinking water, lack of adequate sanitation and indoor air pollution, which are closely linked with and aggravated by persistent poverty and social inequity.

Exposure to environmental risk factors during childhood may not only impact a child's health, but ill-health outcomes may appear in and persist throughout adulthood.

Unsafe and unhealthy environments are violating children's rights to health and represent a serious threat to potential unsustainable development.

Despite rising concern in the scientific community, progress has been slow in identifying and studying some environmental threats on children's health and effectiveness of interventions. Children are exposed to serious health risks from environmental hazards. Their exposure to environmental threats has been recognized as an increasing public health problem in many countries worldwide.

Children are in a dynamic state of growth and therefore, are more susceptible to environmental threats than adults. Many vital functions such as the immune system are not fully developed at birth and unsafe environments may interfere with their normal development.

Environmental risk factors often act in concert and their effects exacerbated by adverse social and economic conditions, particularly poverty. But most environmental hazards are preventable.

Preliminary estimates (from 2002) suggest that up to one-third of the global disease burden is attributed to environmental risk factors. Over 40 percent of this burden falls on children under age 5, who make up only about 10 percent of the world's population.

Inadequate drinking water and sanitation, indoor air pollution, injuries and other risk factors are the root causes of more than 4.7 million annual deaths of children under age 5 from illnesses aggravated by unhealthy environments.

Health and environment links affecting children are numerous and complex. In most cases, exposure to a particular environmental risk is associated with many different health outcomes and a range of environmental exposures may influence a particular condition. This is based on environmental risk factors contributing to global child mortality and morbidity, thereby highlighting the biggest environmental threats to children's health and illustrating potential disease prevention by associating specific risk factors with distinct settings.

A differentiated analysis (from 2003) of the global disease burden revealed that most environmental threats to children's health are associated with persistent poverty and social inequity. The two major problems are communicable diseases due to lack of safe water and sanitation and acute respiratory infections due to high levels of indoor air pollution combined with unhealthy housing. The virtual disappearance of these two leading causes of child mortality, with the transition toward an industrialized society, demonstrates the dominant influence of socioeconomic factors on the nature and magnitude of children's health problems.

However, communicable diseases do not occur exclusively in developing countries and toxic chemicals are not associated exclusively with industrialized countries. There are pockets of poverty in rich countries where certain population groups experience deprivation in their associated health problems, which are similar to those in developing countries.

Also, toxic chemicals increasingly are being used in developing countries, often with fewer controls and regulations than in industrialized countries.

There is a clear shift in the pattern of leading environmental health problems in children. This differential is not only measurable between rich and poor countries but also between population groups within a given country and within any urban agglomeration, ranging from suburban slums with substandard housing to affluent modern suburbs.

Typical modern risks include chronic respiratory illnesses, asthma, immunological disorders, neurological, neurodevelopmental and behavioral effects, as well as childhood cancers. Additionally, there are emerging risks such as environmental allergens, UV radiation, endocrine disruptors, autoimmune effects and other diseases not directly related to quality of the child's environment. Any potential health-and-environment links require further research and a search for other causative factors or combinations of factors.

Environmental risks to children tend to be greater among rural populations compared to urban populations and an unequal disease burden on rural poor may be aggravated further by lack of health care access.

However, the health status of children living in urban poverty is equally preoccupying. A child's well-being is highly dependent on both the quality and availability of water and on how well this precious resource is managed.

Around the world, both biological disease agents and chemical pollutants compromise drinking water quality. Contaminated water causes a range of diseases, which often are life-threatening.

Of waterborne diseases affecting children, the most deadly are diarrheal infections. Diarrhea causes an estimated 1.3 million child deaths annually, constituting about 15 percent of total child deaths under age 5 in developing countries.

As opposed to breastfed infants, bottle-fed infants are highly exposed to unsafe drinking water effects. Intervening in water supply, sanitation and hygiene is estimated to reduce diarrheal incidences, on average, by 25 percent and child mortality by 65 percent.

Availability of at least minimal amounts of water for drinking and other personal purposes is as important as its quality. Already, one-third of the world's population lives in countries facing moderate to high water stress, if not water scarcity, and water tables are falling in every continent. If present trends continue unchecked, it is estimated that two out of three people on earth will live in water-stressed conditions by the year 2025.

Globally, 1.1 billion people today are without access to a clean and adequate water supply. And too little water for basic needs makes it virtually impossible to maintain necessary minimum personal hygiene and sanitary conditions at home.

Lack of adequate sanitary facilities and poor hygienic practices are common throughout developing countries. The lowest levels of service coverage are in Asia and Africa where more than half the rural populations are excluded from any measurable progress in this area.

Globally, 2.4 billion people, most in developing countries, do not have access to improved sanitation facilities. Unhygienic conditions and practices at the household level create a dangerous environment with immediate health risks to children. Also, lack of sanitation facilities in schools helps transmit diseases. Waste dumps situated on almost all major city outskirts provide hazardous environmental conditions to those living nearby, more so to those living as scavengers on such wastes.

Sanitation interventions, both technical and managerial, are needed badly in all areas in houses, schools and the community at large. These must be accompanied by necessary behavioral changes in child and adult populations, which pose a formidable hygiene education challenge to the health sector.

Air pollution is a major environment-related health threat to children and a risk factor for both acute and chronic respiratory disease. Outdoor air pollution, primarily a consequence of traffic and industrial processes, remains a serious problem in cities throughout the world, particularly in mega cities of developing countries. It is estimated that a quarter of the world's population is exposed to unhealthy concentrations of air pollutants.

In recent years, indoor air pollution has received more attention, as a pollutant released indoors is a thousand times more likely to reach the lungs than a pollutant released outdoors. Indoor air pollution is strikingly different in industrialized and developing countries and varies between urban and rural settings. While the main concern in developing countries is exposure to combustion products from biomass fuel and coal, poor indoor environments in the industrialized world are characterized by reduced ventilation, presence of biological agents such as molds and a myriad of chemicals in furnishing and construction materials.

In the past decade, major global demographic, environmental and societal changes contributed to re-emergence of vector-borne and other diseases, many of which have an important impact on children's health and development. A considerable proportion of the disease burden for four key vector-borne diseases, malaria, schistosomiasis, Japanese encephalitis and dengue hemorrhagic fever, falls on children under age 5.

Chemical use has increased dramatically due to economic development in various sectors including industry, agriculture and transport. Consequently, children are exposed to a large number of chemicals of both natural and man-made origin. Exposure occurs through air they breathe, water they drink or bathe in, food they eat and soil they touch (or ingest as toddlers). They are exposed virtually wherever they are – at home, in school, on the playground and during transport.

Approximately 47,000 people die annually as a result of such poisoning. Many of these deaths occur in children and adolescents, are unintentional (accidental) and are preventable if chemicals are stored and handled appropriately.

Each year, accidental injuries account for more than 400,000 deaths globally, the majority in children and adolescents. Most of these occur in low- and middle-income countries. Many of those who survive these injuries suffer lifelong disabling health consequences. In the European region, three to four deaths out of 10 occurring in children between the ages of 0 and 4 are due to injury.

The key to implementing a program on Healthy Environments for Children will be creating a concerted, popular, participatory and inclusive 'movement' addressing the issue in an integrated manner, centering on children rather than individual environmental hazards.

The basic principle on which such a movement builds is that stakeholders at every level can make a difference, e.g., decision makers at international, regional, national and community levels, community leaders, teachers, NGOs, the private sector and families.

Besides the health sector, the movement must involve various other sectors including environment, energy, transport, housing, agriculture and education. Action must be based on scientific evidence to ensure major environmental determinants of adverse health outcomes in children are addressed adequately and the most appropriate interventions considered. It must be driven by strong commitment to act primarily at the local and national level.