 Today's discussion is on the long-term health effects of pesticides. Let's get started by taking a look at this video. Here's concern about the use of pesticides has grown. Many people worry that pesticides may cause long-term health effects. Most of this anxiety stems from the public's fear that the food we eat is contaminated with pesticide residues. But for people who work around pesticides, there is another concern. What are the possible health effects of working around pesticides? If a worker is exposed to a dose large enough to produce immediate illness or injury, the effects are obvious. But what happens if somebody is repeatedly exposed to quantities too small to cause any immediate harm? Or what about the person who gets poisoned or injured by a pesticide and then recovers? Could this person suffer delayed long-term health problems as a result of this single exposure? In the next several minutes, we will talk about some of the possible long-term health effects of pesticide exposure in the workplace. And answer some of the questions you may have about long-term health effects of pesticide exposure. The most common concern about pesticide exposure is the fear that it might cause cancer. Only one group of pesticides, the arsenicols, has been proven to cause cancer in humans. But many pesticides have been shown to cause cancer in laboratory animals. An animal's response to a chemical under experimental conditions does not necessarily reflect what will happen to people exposed to the same chemical. Even closely related species such as rats and mice often respond differently to chemicals. So it's very possible that a certain pesticide which causes cancer in some laboratory animals will not do so in humans. Also, the doses given to experimental animals are much larger than the amount of exposure a person would receive. Therefore, the results of laboratory experiments may make a chemical appear more hazardous than it is. Animal testing is not a perfect way to predict human risk, but it provides us with one of the best available means of evaluating risk. That's why pesticides that cause cancer in animals must be regarded as a possible cancer risk for people. Another long-term health risk associated with a few pesticides is reproductive damage. Reproductive effects include several kinds of problems. One possible problem is sterility, which is the inability to become pregnant or cause pregnancy. Miscarriage is another reproductive problem. Some chemicals can interfere with the normal development of the unborn child, causing physical or metal defects. Exposure to certain chemicals during pregnancy can result in a stillborn child, meaning the child dies during pregnancy. Finally, there are chemicals which permanently change a person's genetic makeup. A person exposed to such a chemical may give birth to or father defective or stillborn children many years after the exposure. Genetic defects can be passed to future generations. In the 1970s, male infertility was linked to the fumigant DBCP. Many men working in the manufacture of DBCP began to notice that they were not fathering children. Investigations show that these men had sperm counts too low to allow them to cause pregnancy. Some had no sperm at all. When it became apparent that DBCP was responsible for the problem, it was taken out of production and is no longer produced or used in the United States. Some of the affected men regain their ability to father children, but others remain sterile. Many pesticides are nerve poisons. This is how they kill the pests they control. Unfortunately, some of these pesticides can affect the nervous systems of people. If an affected person receives treatment soon enough after exposure, the damage can usually be reversed. But under some circumstances, exposure to certain pesticides may cause long-term or permanent damage to the nervous system. Certain pesticides have caused long-term nervous system damage to workers involved in their manufacture. Production of two pesticides, Kepone and Fozvell, was discontinued when it became known that these materials were causing nervous system damage among factory workers. One of the pesticides, Fozvell, belongs to a group of commonly used insecticides, the organophosphates. Other organophosphates that are not used in pesticides can cause delayed nervous system damage. Most of the organophosphate insecticides commonly in use, such as melothion, dimethylate and diazinone, to name a few, have not been known to cause similar problems. But since members of the same chemical family can cause long-term illness, the possibility of long-term damage must be considered when handling organophosphate pesticides. Another group of pesticides, the fumigants, can cause permanent nervous system damage if exposure is great enough. A few pesticides can cause severe and permanent lung damage. A high level of exposure to the herbicide periquat or grimoxone causes the lungs to fill up with scar-like tissue. This process is called fibrosis. The damage is irreversible and the fibrosis continues to form long after exposure has ended. After several days or weeks, the damage to the lungs kills the affected person. There are other organs which can be permanently damaged by excessive exposure to certain pesticides. The kidneys filter the blood to remove impurities, including pesticides. Because these impurities are collected and concentrated in the kidneys, these organs are especially susceptible to damage. The liver is also involved in cleansing the blood. So the liver comes in contact with any pesticides that get into the bloodstream and, like the kidneys, is susceptible to injury. Long-term damage to the skin can be caused by pesticide exposure. A number of pesticides, including benylate, malathion, and formaldehyde, produce an allergic reaction in some people. This reaction may include itching, redness, water blisters, or other types of skin irritation. Often, a person has to be exposed to such a pesticide many times before an allergic reaction develops. But once it happens, the reaction will occur every time the person is exposed to that pesticide. Now that we've discussed the kinds of long-term damage that can result from exposure to pesticides, we'll describe ways that exposure can occur. Pesticides can get into your body through your eyes or skin, or can be inhaled into your lungs. They can also get into your body if you eat or drink something that is contaminated with pesticides. Skin contact is the most common route of exposure for workers. Many pesticides pass quickly through the skin and into the bloodstream, so always protect your skin when working around pesticides. Your skin can get exposed when you mix, load, apply, or otherwise handle pesticides. Overhead dripping from treated surfaces and settling of spray droplets or mist clouds can contaminate your head and the back of your neck. You can also get exposed if you touch contaminated pesticide application equipment, or if you enter a chemical storage area and come into contact with pesticides. Even if you don't work with pesticides, you can get exposed when you touch treated surfaces. On occasion, whole crews of workers have become ill because they were instructed to enter treated fields too soon after a pesticide application. Usually, if you wait the required amount of time before entering treated areas, the level of pesticide present is too low to cause immediate illness. But repeated contact with small amounts of pesticides remaining on treated surfaces could have a long-term impact on your health. That's why you must always protect your skin. Restricted entry intervals are waiting periods, which let pesticides break down into less toxic substances. If you need to enter areas with restricted entry intervals in effect, you and your supervisor must make sure you wear all the required protective clothing and equipment. You may swallow traces of pesticide left on your hands. If you touch treated surfaces or work with pesticides, then eat, drink, or smoke without washing your hands. So after handling pesticides, repairing or cleaning pesticide application equipment, or touching treated surfaces, wash your hands before you eat, drink, or smoke. The amount of pesticides you swallow at any one time when you eat with contaminated hands will probably be too small to make you sick. But if you are habitually careless, you may eventually suffer. If pesticides get into your eyes that can cause serious injury, some can cause permanent damage. Your eyes can get exposed if a pesticide splashes into them, or they're exposed to spray mists or pesticide dust or vapor. So you must always wear a face shield or other eye protection when working with pesticides. Eye contamination can also occur if you rub your eyes with contaminated hands or sleeves. If you mix, load, or apply pesticides, or if you help clean up a spill, you could inhale toxic vapors or dust. If the pesticide label tells you to use respiratory protection, you need a special respirator approved for use with pesticides. The respirator must fit your face well. If not, some unfiltered air will be drawn in through the sides of the respirator when you inhale. Even if you don't handle pesticides, you can breathe them in if you are in an area under treatment, or if you go into a treated area before the dust, vapor, or mist has completely settled. You may also inhale pesticides if they drift into the area where you are working. Remember when you work with pesticides or near pesticide application or storage areas, a certain amount of contact is almost unavoidable. You and your employer need to do everything possible to keep that contact at a minimum. Personal hygiene in the workplace may be inconvenient in many situations, but it pays to take the time to wash your hands before lunch and break. Bathe at the end of each work day and launder your work clothes before reuse. If your employer doesn't provide you with proper protective gear or a clean place to store things and to wash up, or if you don't use the protective equipment you've been given, or fail to bathe and change your clothes after working around pesticides, your health may be affected in the future. Well, we've covered a lot of material. Does anyone have any questions? Is there really any proof that pesticides cause long-term illness? Most pesticides have been used for years with no indication of long-term damage to people, but a few have shown to be harmful and have been banned. Some have been eliminated because there is evidence they could cause long-term health effects. A number of pesticides used today are suspected of being harmful because they are related to chemicals known to cause long-term damage. Keep in mind that not all pesticides are alike. The word pesticide includes a large number of chemicals with very different characteristics. The health impact of one pesticide does not indicate anything about the health impact of another chemically unrelated material. In other words, proof that one pesticide causes long-term health effects doesn't tell us anything about the possible danger of other pesticides. What proof do we have that pesticides don't cause long-term health effects? And if they might be dangerous for us, why are we still using them? If someone gets exposed to something and starts to feel sick soon afterwards, it may be easy to show that the substance made that person sick. Likewise, if a group of people are habitually exposed to a substance which other people never come in contact with and many of the exposed people develop the same illness, there is strong evidence the substance is responsible for the illness. But it is almost impossible to prove something is completely harmless. Because there is no way to know for sure that pesticides will not cause long-term health effects, it is essential each worker minimize exposure by using protective equipment by observing common-sense safety rules and by keeping out of treated areas until it is considered safe to re-enter. I've been working with pesticides for more than 20 years now. What I'd like to know is if they're so dangerous, how come I haven't gotten sick? The message here is not that all pesticides are harmful in all cases, but that some pesticides can be harmful in certain situations. It is very possible for you to work with a large variety of pesticides for many years and never experience any ill effects, even if you don't always use the recommended protective equipment or follow safe procedures. But that is like saying you can smoke two packs of cigarettes a day for the next 20 years and never get lung cancer or emphysema or any of the other maladies commonly associated with cigarette smoking. The problem is that although you might not get sick, on the other hand, you might. So why take a chance? Why are test animals given such huge doses? People live for many years, but a lab rat only lives for a couple of years or so. So total human exposure time is likely to be longer and people have a longer time in which to develop an illness if exposed to a chemical with delayed harmful effects. In an attempt to make up for this time difference, larger doses are given to test animals. Another reason for the large doses is to cause a rapid, observable response to the substance under study. This helps researchers reach conclusions as quickly as possible. Most scientists agree that animal experiments aren't a perfect way to show something will affect people. That's because the large doses used don't reflect human exposure. And because animals are not humans, animals do not necessarily respond to a specific chemical in the same way as people. Nevertheless, even though animal testing is not a perfect way to predict human outcomes, it is one of the few tools we have to determine how a chemical may affect humans. And until scientists find a better method, animal testing and pesticides will continue. I work with a lot of different pesticides. Is it more dangerous to be exposed to a combination of pesticides than to just one? We don't know much about how exposure to two or more pesticides or a combination of pesticides and other chemicals can affect health. Every day we are exposed to an enormous number of synthetic and natural substances apart from pesticides. It's impossible to even list all the possible exposures we experience, let alone the health impact of each combination. Studies have shown that combinations of some chemical substances may be harmful even though either of the chemicals alone would not be life-threatening. And it is known that liquor and certain drugs can influence the way a person will be affected by exposure to some pesticides. Some combinations of pesticides could cause more harm than the sum total of the damage they could do if encountered individually. Our uncertainty is yet another argument in favor of doing everything possible to minimize exposure to all pesticides. Yes? What are inert ingredients and are they dangerous? Inert ingredients are substances added to pesticide formulations. This one is 46% inert. They're not intended to harm the target pest, but they make the pesticide work better. They may allow for a more even spray distribution or help the pesticide stick to a treated surface. They may make it possible to mix the formulation with water. Some so-called inert ingredients are actually quite toxic to humans. And manufacturers are now required to list the names of highly toxic inerts on the pesticide label. Many companies have switched to less dangerous inerts in an attempt to make their products safer. However, as with most other substances, not everything is known about the long-term health effects of exposure to all the inerts used in pesticide formulations. As more is learned, some inerts are being replaced by other materials that are believed to be safer. Yes? I got poisoning's job a while back. I feel fine now, but should I worry about getting sick again? If you suffered pesticide poisoning and then recovered, your body probably resolved the damage that caused your symptoms. Usually the kind of illness caused by a single acute poisoning incident has no relation to the long-term effects the same pesticide might cause. So the fact that you get acutely ill from a pesticide doesn't mean that you'll have some ongoing health effect later on. On the other hand, you might never get acute pesticide poisoning, but this doesn't guarantee that you won't suffer long-term health effects if you're repeatedly exposed to low levels of pesticides. I've been exposed to a lot of different pesticides, I think. Is there any way that I can have my blood tested to find out what kind of chemicals I've been exposed to, or any other way that I can find out what chemicals are in my body? Certain insecticides lower the level of a substance in the blood called cholinesterase. If your cholinesterase level gets too low, you'll start to feel sick. A doctor can measure your cholinesterase level with a simple blood test. Exposure to some pesticides can be detected, not by a blood test, but by an analysis of fatty tissue. These pesticides, which include lindane, chlorodane, heptachlor, metoxachlor, among others, accumulate in the fat and remain there for many years after exposure has ended. A doctor could use fatty tissue analysis to investigate the possibility that exposure to such a pesticide may be related to the onset of certain illnesses. However, the presence of a fat-soluble pesticide in your body does not mean that you are going to get ill. As far as we know, some fat-soluble pesticides can be stored in the body for a lifetime without causing harmful effects. For most pesticides, a blood test or some other laboratory test can't tell you if you've been exposed to pesticides previously. The only way for you to find out what you may have been exposed to is to find out what chemicals are in your workplace. You have a right to insist that your employer give you the names of the pesticides and other chemicals in the workplace. Does the pesticide label tell me everything I need to know about the possible long-term health effects of pesticide exposure? No. Every pesticide label has a signal word that gives you a general idea of how likely it is the pesticide could cause immediate poisoning or injury. The label also has a section that talks about the immediate effects of exposure. But the signal word and the precautionary statements only address the kinds of illness or injury you might feel right away. It's very rare for a label to even mention the known or suspected long-term problems associated with the pesticide. The EPA and chemical companies are starting to focus more attention on long-term health effects and a few labels now have statements related to long-term effects. In the future, it's likely the labels will focus more on the problem of long-term health effects. It's unfortunate we don't have all the answers when it comes to possible long-term health effects of each and every pesticide we have. Like with other branches of chemistry, including pharmaceutical chemistry, food science, there are and perhaps always will be uncertainties. But one thing is sure, nothing can hurt you if you don't get exposed. Even with substances known to cause long-term damage, a certain amount of exposure must occur before any damage is done. So as pesticide users, you need to keep your exposure at a minimum by using protective equipment, common sense, safety practices and good basic personal hygiene. In other words, remember that a potential for long-term damage may exist. And when you handle pesticides, do everything possible to minimize your exposure.