FROM CHILDREN’S toys and the clothes we wear, to the food we eat and the air we breathe — even what seem to be benign can harm us. Indeed, the 16th century German-Swiss alchemist and physician Paracelsus had exclaimed, “All substances are poisons, there is none which is not a poison. The right dose differentiates a poison and a remedy.”
 RESIDENTS of the Southville Housing Project, a government relocation site in Cabuyao, Laguna, used to live next to a dumpsite and had to resort to wearing a mask to avoid its harmful and unbearable stench. [photo by Alecks P. Pabico] |
Poisoning is a global problem, and as our world becomes more complex, the risk of poisoning has increased. Yet it is highly likely that poisoning cases are underdiagnosed, partly because we know so little about the effects of small doses of chemicals during the development of our bodies. Recall that it was only three decades ago that we realized the hazards posed by lead, which had been a popular ingredient in paint and other everyday objects. By then generations had been exposed to the substance, which in toxic levels can cause retarded mental growth in children and can mimic intestinal parasitism (abdominal colic and anemia).
Still, even today, some people apparently have failed to heed warnings regarding the use of lead; in recent months, for instance, the major U.S. toy manufacturer Mattel was forced to recall thousands of its products after discovering that a subcontractor in China had used lead paint on the toys.
The Mattel case highlights the fact that in many instances, poisoning is entirely preventable; there are, however, factors that need to be present. Experience has shown us again and again that outside of malicious intent, poisoning occurs mainly because of ignorance, complacency, and the human compulsion to take unnecessary risks.
Access to the right information is thus vital in the prevention of poisoning. Vigilance, which seemed to be instrumental in avoiding disaster in the Mattel case, is needed as well. So, too, is caution, especially in these times.
There are many kinds of toxicants. These days, we are often unaware of the natural toxins found in the environment, including those in plants; there is even a growing popular perception that anything that is “all-natural” must be good, and therefore safe. Yet there are the likes of cassava, which, if processed improperly, can cause cyanide intoxication.
Interestingly enough, ancient civilizations possessed a wide range of knowledge regarding natural poisons and used this in their daily lives, from hunting to rituals, to curing illnesses. The first documentation of the use of natural poisons for their medicinal properties was found in Egyptian papyrus scrolls that scholars believed were from 1550 B.C. The Greeks and Romans later used poisons in political activities and in executions.
From the Middle Ages to the Renaissance period, political assassinations were often carried out with poisons. In the 19th century, the Spanish chemist and physician Mateo Josep Bonaventura Orfila published Traite des Poisons, which described his scientific procedures in testing animals and developing methods for the chemical analysis of poisons in body fluids and tissues. The groundbreaking work correlated biological and chemical information, paving the way for modern toxicology and the application of analytical procedures in forensic science.
TODAY WE are more conscious of the hazards posed by chemicals in manufactured products such as household and industrial cleaners and agricultural pesticides. But there are times when we are careless in the way we use and store these. Our attitude toward pharmaceuticals also leaves much to be desired, since far too many of us tend to assume that just because medicines are supposed to be part of the treatment of illnesses, all their effects are beneficial.
At the same time, there are far too many who should know better yet even help others put themselves at risk. Case in point: drugstores that sell prescription medicine to people who are unable to show a doctor’s prescription. This is a dangerous practice since it can lead to the misuse of the medicine, including overdosing. Isoniazid, an antituberculosis drug, is particularly nasty when taken in an amount that is more than what is needed: It can cause metabolic acidosis, convulsions, coma, and death.
Vanity has also become hazardous to our health. Men wanting to look muscular have been persuaded to take anabolic steroids that result in life-threatening liver shutdowns. Women and even young girls obsessed with keeping their figures trim have turned to unregistered slimming pills that can cause serious catabolic and toxic physiological changes in the body, damage the cardiovascular system, and even perversely alter one’s psychological makeup. I once gave a talk at an exclusive girls’ school some years back and was surprised that teenaged girls were using such pills. I was more shocked to find out that the girls’ mothers were the ones who convinced them to use the pills in the first place.
The danger lurking underneath an obsession over appearances exists as well in the grocery and palengke (wet market). To entice more buyers, some unscrupulous farmers and vendors resort to chemicals to enhance the way their produce look. In the last decade or so, there have been several media reports on the use of formalin and petroleum on vegetables and fish. The purported reason: to preserve the “freshness” of the produce. The other effect, however, is additional toxicity to what is supposed to be a source of nourishment.
In our 24/7 world, we have also heard of “toxic schedules” and “toxic jobs,” referring to a high-pressure atmosphere in the workplace. But there are jobs that expose workers to literal poisoning, which can actually be prevented with the right safety equipment and procedures. Solvents, for instance, are the most commonly used chemicals in industrial processes. Although they come in different chemical formulations, they uniformly affect the nervous and blood systems, as well as the liver, heart, and the respiratory system.
Unfortunately, companies are not uniform in their efforts to keep the workplace safe from chemical pollution, and their employees from the risks of being exposed to solvents. One way to find out if a company is compliant with safety standards is to ask their workers what “MSDS” and “PPE” mean. MSDS stands for material safety data sheet, which provides information about how chemical substances should be handled, as well as its toxicity and health effects, and first aid procedures, among other things. PPE is short for personal protective equipment, or gear that a company should provide to keep an individual in its premises free from harm.
Mining is another occupation that exposes the worker to all sorts of risks. In terms of poisoning, we have seen sulfide inhalational exposure among miners working in geothermal sites. Sulfide emits a strong rotten egg odor, but over time — under chronic low-dose exposure — workers lose the ability to tell if there is a high leakage of this gas. Inhalation of sulfide can alter the configuration of our hemoglobin so that these cannot be relied upon to carry precious oxygen to vital tissues and organs, thereby leading to convulsions, metabolic acidosis, and cardiovascular collapse.
Almost two decades ago, there was a mining boom in Mindanao. The method used in mining the gold, however, was the inefficient, crude, and dangerous mercury extraction process, in which mercury vapors were released into the environment and contaminated communities. The predominant toxicity of mercury is nervous system damage. (And while we know that schoolteachers do not have it easy, last year teachers and students alike were put at risk of mercury poisoning during a science experiment gone terribly wrong in a school in Parañaque. Several students and school personnel, including teachers, had to seek medical help; the school was ordered closed for days so that it could be cleaned thoroughly.)
Then there are careers like firefighting, which exposes one to the risk of carbon monoxide inhalational poisoning. This is the same hazard, though, that threatens drivers who do not maintain their vehicles.
YET EVEN a jeepney driver who religiously keeps his vehicle in tiptop shape may not be free from falling sick from inhaling air that is heavily polluted by fumes from smoke-belching cars, trucks, motorcycles, and yes, jeeps. Neither would a well-conditioned athlete, apparently. Just recently, officials of the 2008 Olympic Summer Games that will be held in Beijing voiced their worries over what could happen to athletes who would be competing while breathing in the toxic air in the Chinese capital. One of the costs of China’s new prosperity is air pollution, brought about not only by its multiplying factories and coal-fired plants, but also by its citizens’ growing fondness for cars and more cars.
It’s a problem that is certainly not unfamiliar to Filipinos, many of whom now have respiratory ailments because of the deteriorating air quality of our cities and towns. But it’s not only the air that we have managed to poison; industrial and household waste — some of which contain chemicals that are carcinogenic — have turned our seas, rivers, and lakes into toxic soups. This raises the risks that the fish, clams, and crabs that we put on our dinner tables could well send us to the hospital.
There is no doubt that we are part of the reason why new forms of poisoning are emerging at an ever-increasing pace. That’s the bad news. The worse news is that the Philippines has been slow in producing the human and technical resources needed to address the multiplying problems of poisoning. In a country where doctors are willing to retrain as nurses just so they can work abroad, the field of toxicology is unattractive from an economic perspective even when compared to other medical specialties. Analytical laboratory systems are also poorly developed, and the few labs that exist could use regular quality-control checks. Not surprisingly, problems of toxicology are approached in a reactive, instead of a preventive, manner. Local toxicology research has also lagged behind those on other health issues.
There is weak government incentive to invest in toxicology because it is perceived to be a low priority when compared to other public-health problems in a resource-poor country. The number of local toxicology cases is supposedly small; even the pharmaceutical industry, in fact, has been reluctant to invest in service-item, yet “orphan” drugs that are used to treat many cases of poisoning. As a result, access to antidotes is low — that is, if these are available at all.
For instance, we used to have antidotes for the envenomation from cobras, which can paralyze their victims, the most common of whom include soldiers, forest rangers, agricultural workers, and golf caddies. Today we are often short of these life-saving antidotes, and that is due most probably to the drug industry’s assessment that producing these would just result in a poor return of investment. The Research Institute of Tropical Medicine (RITM) does produce some 5,000 vials of cobra antivenom a year, but it usually runs out of stock after a few months.
The statistics on toxicology cases, however, may be grossly inaccurate, given the lack of hospital resources and expertise to deal with these. Since the figures count only the cases attended to, it leaves out those that were sent elsewhere for some reason or another, or those that were misdiagnosed altogether. Excluded, too, are poison victims who failed to get medical help on time and those who opted not to seek help at all.
For sure toxicologists need to be communicators in their community and to be always on the ready to provide their services — whether or not these are appreciated. We need to explain to people the role of toxicology in our everyday lives. But we also need to emphasize that toxicology is a shared responsibility of the government, industry, and the sciences. The current lack of coordination and the seemingly neglected investment on toxicology has only placed us unnecessarily in harm’s way.
Dr. Kenneth Hartigan-Go is a medical toxicologist who is connected with the Ateneo School of Medicine and Public Health and Medical City. For more information about poisons, contact the National Poisons Center at telephone number 524-1078 or write to the Philippine Society of Clinical and Occupational Toxicology, Inc., c/o NPCMC Ward 14-A, Philippine General Hospital, Taft Ave. Manila.