Safe Planet Safe Planet

Chemicals

What are Chemicals?
What happens when chemicals are released to the environment?
Why are chemicals of interest today?
How can the risks of chemicals be identified?
What types of chemicals pose risks to health and the environment?
What can be done to address the risks posed by hazardous and toxic chemicals?

What are Chemicals?

All living and inanimate matter is made up of substances that are formed by different combinations of the more than 100 elements found in our world, such as the two major components of the air we breathe – nitrogen (~80%) and oxygen (~20%). Simply stated, a chemical may be either an element or a compound that is formed by a combination of elements.

Top

What happens when chemicals are released to the environment?

Upon release into the environment, a chemical will be subject to natural transformation and transportation processes that are influenced by:

Top

As a result of the effects of these various factors, a released chemical will be:
Upon release into the environment, a chemical will be subject to natural transformation and transportation processes that are influenced by:

Eventually, as a result of this multimedia behaviour, the chemical and its transformation products will be distributed between soil, sediment, water, air, plants, animals and humans.

Top

Why are chemicals of interest today?

Since the large scale production of chemicals began in the middle of the 19th century, the use of chemicals has grown steadily and chemicals have now become an essential component of modern societies, serving in a wide variety of roles that establish and/or preserve an elevated standard of living in countries at all stages of development.

Virtually every man-made product involves the use of chemicals in some manner and new chemicals are developed every year in response to the constant demands for new and improved materials (e.g. plastics, cosmetics, drugs), enabling advances to be made in such high technology areas as health care, bio-engineering, electronics and telecommunications.

However, the large scale production and use of chemicals has been accompanied by the release to the environment of many chemicals that have degraded environmental media and resulted in the exposure of humans and wildlife to levels of chemicals that cause adverse impacts on human health and the environment. As a result, numerous hazardous and toxic chemicals have become priorities for risk management action at the national and international levels.

In addition to the tens of thousands of chemicals that are intentionally produced for commercial purposes, some chemicals are unintentionally produced as by-products in industrial, manufacturing and combustion processes. These chemical by-products may be present as contaminants in products, articles and wastes or be released directly into the environment, thus contributing to the burden of chemicals in the environment and, ultimately, to the exposure of humans and wildlife. Some by-products, such as polychlorinated dioxins and furans, have been identified as toxic to humans and wildlife and are priorities for risk management action at the national and international levels.

Public concerns about the adverse impacts of chemicals on human health and the environment have made the sound management of chemicals and their associated wastes an essential component of overall public policy in countries at all stages of development. While chemicals can make significant contributions to resolving many modern issues (e.g. the use of pest control products to control vector borne diseases such as malaria), if not properly managed they can cause significant damage to human health and the environment.

Top

How can the risks of chemicals be identified?

To assess the health and environmental risks of chemicals, their physical, chemical and toxicological properties need to be assessed along with estimates of exposure of humans and environmental organisms.

Because the specific properties, release conditions and environmental fate are unique to each substance, chemicals need to be assessed systematically to see whether they will be broadly distributed following release to the environment or will preferentially concentrate in one medium (air, water, sediment, soil, or biota). Such systematic assessments can identify the nature and extent of local, regional and global impacts of chemicals that are released to the environment.

In assessing the risks posed by a chemical it is important to consider releases from the widest range of activities including during manufacturing and processing, handling and transportation, accidents involving manufacturing and transportation, the use of products and articles, and disposal of wastes from manufacturing processes and from the end-of-life stage of products. This is sometimes referred to as assessing the “life cycle” of the chemical.

Top

What types of chemicals pose risks to health and the environment?

The following are examples of types of chemicals that have been shown to pose unacceptable risks to human health or the environment.

Top

What can be done to address the risks posed by hazardous and toxic chemicals?

The wise use of chemicals is important in establishing and maintaining a higher standard of living in countries at all stages of development. However, the failure to properly assess and manage the risks posed by the use and possible release to the environment of chemicals can seriously undermine sustainable development initiatives at the national, regional and global levels.

Governments are paying increasing attention to the need to take risk management actions to protect their populations and environment from the threats posed by toxic chemicals. Risk management actions include the development of measures to prevent or control the release of problem chemicals at appropriate stages in their life cycle – including research and development, production, transportation, use and waste disposal.

Top

Safe Planet on Facebook Safe Planet on YouTube

UNEP Basel convention Rotterdam convention Stockholm convention FAO
Privacy Statement | Copyright Disclaimer | Contact us
Safe Planet © 2011