|Toxics and Health: - The Potential Long-Term Effects of Industrial Activity (WRI, 1994, 68 pages)|
In many parts of the world, toxicants are
accumulating in the environment. If the projected five-fold increase in global
economic activity over the next 50 years is based on the same technology as the
current system, the rate at which toxic materials accumulate will markedly
increase. The prevalence of toxic substances will cause direct and indirect
effects on human and ecosystem health. Certain conditions being reported in the
medical and ecological literature may be early indications that environmental
toxins are affecting human and ecosystem health as anticipated.
In 1962, Rachel Carson warned the public that widely used substances, once considered safe, could wipe out entire ecosystems.1 Over the past thirty years, we have significantly improved our understanding of many of the impacts of certain industrial pollutants and have made significant strides in controlling these. Today, however, researchers around the world are beginning to connect industrial pollution to more subtle, acute, and chronic problems threatening the health of people, wildlife, and ecosystems. These connections suggest that the control of individual pollutants is not the answer and that industrial economies need to be fundamentally restructured.
In nature, most systems continuously renew themselves. But industrial processes alter the natural flow of materials, causing toxic substances to reach levels in the environment that far surpass natural levels and introducing novel chemicals into the environment on a vast scale.2
When toxic substances accumulate in the environment and in food chains, they can profoundly disrupt biological processes.
Their effects may be acute or chronic. They can act directly, indirectly, or in combination, and they may cause cancer or malfunctioning of the systems that regulate metabolism, reproduction, behavior, or immune response. Individuals of all species can be affected and the interplay between individuals and species altered.
The risks posed by environmental contamination are not necessarily obvious. For example, people or animals whose immune responses are suppressed may take longer (or be unable) to recover from infectious diseases. Animals may find themselves unable to obtain sufficient food or avoid predators. Exposure to neurotoxins can diminish parenting instincts. Endocrine disruption can lead to abnormal development of sexual anatomy or behavior.3 Fragmentary but growing evidence indicates increases in female breast cancer, decreases in sperm count in men throughout the developed world, and increases in abnormalities and malfunctioning of male reproduction systems in both humans and wildlife, all since the massive increase in production and use of synthetic chemicals began around 1940. Recent findings also strengthen the link between these suspected environmental toxins and other health problems in humans, including chronic diminished brain function across broad groups of individuals living or working in heavily contaminated areas.
As our understanding of the impacts of industrial pollution grows, we are also improving our knowledge of how large a burden we are placing on the environment. It is clear that environmental degradation and dissipation of substances into the environment occur when materials are extracted or processed and when end products are used or discarded. Detailed information on exactly where toxic materials are released to the environment, or in what quantities is just starting to be gathered, but it is already apparent that the amounts of long-lived toxic materials that industry reports it releases to the air, waterways, or land are vastly underestimated and that, without fundamental changes in industrial processes, these amounts will continue to increase dramatically.4
As toxins accumulate in the environment and in the food chain, their toll on human and ecosystem health is expected to grow and become more apparent. The threshold at which these substances will alter nutrient cycles worldwide, severely disrupt ecosystems, or severely harm human health, and when these may be reached, will remain unknown until we better understand more about the important physical and biological processes and the total burden that is being placed upon the environment. The implications of these so-called loadings are clear, however. The grave risks posed by these substances, combined with potential increases in their flows as manufacturing expands, increasingly justify efforts to eliminate waste at every step of industrial processing, thus closing the material cycle.
The inquiry into the effects of environmental toxification is encouraging researchers to look at a variety of challenges in new ways. Modelers are devising new tools that place economics squarely in the realm of the environment.5,6 Industrial ecologists are studying ways to eliminate whole stages of processing, thereby eliminating the attendant waste. Toxicologists, ecotoxicologists, wildlife biologists, epidemiologists, engineers, and ecological risk managers are taking a fresh look at acute and chronic problems prevalent in ecosystems, wildlife, and people. And policy analysts are conceiving new ways to stimulate the transition to a cleaner, more efficient industrial system.