I don't like spinach and I'm glad I don't,
because if I liked it I'd eat it, and I just hate it.
Clarence Darrow, Quotations Digest
Playing with Pesticides
Recent anecdotal reports of headaches, dizziness, muscle twitching, vomiting, blurred vision, and other health effects associated with excessive exposure to chlorpyrifos have caused the EPA and industry to implement measures to protect consumers from overexposure to the pesticide. However, a new study shows that using chlorpyrifos products even in a manner consistent with the manufacturer's instructions can lead to exposures well above the level considered safe by the EPA. In addition, the study suggests that children run a particularly high risk for dangerous chlorpyrifos exposure.
Chlorpyrifos is a broad-spectrum organophosphate insecticide that has risen in popularity as the use of other pesticides, such as aldrin, dieldrin, and chlordane, has been phased out. Sold under the brand names Dursban and Lorsban (both manufactured by DowElanco of Indianapolis, Indiana), it is currently one of the most widely used pesticides in the United States in both household and professional applications.
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Toxic toys? A new study suggests children may be at risk of consuming dangerous amounts of chlorpyrifos from the surfaces of toys. |
It is in household applications that potentially hazardous exposures may occur, say scientists from the Environmental and Occupational Health Sciences Institute of Rutgers University in Piscataway, New Jersey, who authored the new study. The study, published in this issue of EHP, investigates the level of chlorpyrifos that adheres to surfaces and objects in a room after it has been treated with the pesticide and ventilated according to the manufacturer's instructions. The authors propose that the semi-volatility of the pesticide allows it to continue to be deposited on surfaces in a treated room weeks after application; it may adhere to objects that are brought into the room hours or days after the pesticide is applied, such as children's toys.
To test this proposal, the authors treated rooms in two apartments with Dursban and then opened windows and used fans to ventilate the rooms for the recommended four hours. After a fifth hour, they placed groups of plastic and plush toys in the rooms, and periodically thereafter removed one plastic toy and one plush toy to measure surface chlorpyrifos contamination. What they found was that significant amounts of chlorpyrifos were volatilizing from other surfaces and adhering to the toys long after the pesticide was applied; in fact, peak deposits on surfaces in the room took place 36 hours after the original application.
The authors conclude that applications of chlorpyrifos could result in significant doses of the pesticide to children who play in recently treated rooms. For a child between the ages of three and six, the total nondietary dose of chlorpyrifos after normal home treatment was calculated by the authors to be about 208 micrograms per kilogram of body weight per day (µg/kg/day)--well above the EPA's reference dose for chlorpyrifos of 3 µg/kg/day (the daily dose that is unlikely to cause any harm over a lifetime). For children who exhibit high levels of hand-to-mouth activity, the authors conclude that this dose could be as high as 634 µg/kg/day. The study also demonstrates that dermal and oral exposure to the pesticide via toys and other surfaces may present a greater risk to children than inhalation of chlorpyrifos.
This study is likely to shed doubt on whether a June 1997 agreement between the EPA and industry to reduce consumer exposure to the pesticide will be sufficient to protect children. That agreement calls for the elimination of chlorpyrifos in pet products such as flea dips and shampoos and in broadcast pesticide products such as foggers. The agreement also commits chlorpyrifos manufacturers to take steps to ensure that the pesticide is not applied on inappropriate surfaces such as toys, drapes, and furniture. New warning labels, based on the agreement, should begin appearing on chlorpyrifos products sometime this year.
However, the new study suggests that even when the greatest care is taken to ensure that the pesticide is applied only to surfaces that children are unlikely to contact, there is still the chance that it will end up on other, absorbent surfaces such as toys and pillows. Though the treatment used in the study apartments was a broadcast application of chlorpyrifos, which industry and the EPA have already agreed to phase out, the research indicates that more care must be taken than previously thought to avoid exposures to this pesticide. It also signals that regulators can no longer simply measure air concentration to determine if dangerous levels of certain pesticides exist in a room.
Not Enough Spinach?
Children in the United States generally do not eat as much of some food groups as the U.S. Department of Agriculture (USDA) recommends, and many children do not meet USDA recommendations for any of the five food groups, according to a recent study published in the September 1997 issue of the journal Pediatrics. Researchers at the division of cancer prevention of the National Cancer Institute compared the USDA's 1989-1991 Continuing Survey of Food Intakes by Individuals to the recommendations contained in the USDA's 1992 Food Guide Pyramid. They found that only 1% of children in the survey met all recommendations, but that these children also tended to consume too much fat. Overall, about 30% of children were found to meet recommended dietary allowances (RDAs) for fruit, grain, meat, and dairy, while about 36% met the RDA for vegetables. Over 45% of the children surveyed met none or only one of the recommendations.
The USDA recommends that children eat 6-11 servings of grain per day, 3-5 servings of vegetables, 2-4 servings of fruit, 2-3 servings of dairy products, and 5-7 ounces of meat. In contrast, the study found that children are eating on average only 5.8 servings of grain, 2.6 servings of vegetables, 1.3 servings of fruit, 2.1 servings of dairy products, and 3.9 ounces of meat. The weight of food that composes one serving varies by food and by the age of the child.
The results showed that children are eating less healthily than adults, who fared better in a similar study published in a 1997 supplement to the American Journal of Clinical Nutrition. In that study, which was also based on information from the 1989-1991 USDA survey, it was found that 9% of all adults failed to meet the RDAs for all of the food groups. The new study shows that an even greater percentage of children--around 16%--met none of these dietary standards. Also, whereas the children in the survey were also consistently found to have too much fat and added sugars in their diets, the adults who met other Pyramid recommendations were likely to consume fat and added sugars at levels close to those recommended.
Though on average the diets of U.S. children were unhealthy by USDA standards, some demographic subgroups fared better in the analysis than others. In particular, teenage males were found to be much more likely to meet recommendations for the grain, vegetable, dairy, and meat groups than teenage females or younger children. Females ages 6-11 were the most likely to eat the recommended amount of fruit. Black and Hispanic children were found to eat more meat and vegetables than white children, who consumed comparatively higher amounts of grain and dairy foods. Poorer children were found to consume less fruit than wealthier children, but on the whole, family income was not a predictor of eating patterns.
Fatal Fungus
Something is rotten in the state of Ohio. Over a period of four years beginning in January 1993, at least 34 infants in the Cleveland area developed pulmonary hemosiderosis--bleeding of the lungs that can lead to coughing up blood, nose bleeds, chronic cough and congestion, and anemia--and ten of the sick children have died as a result of the disease. It is believed that the mold Stachybotrys atra is to blame.
The mold produces the toxic trichothecene satratoxin H, which is carried via spores into the respiratory airways, wreaking particular havoc on infants' vulnerable lungs. It is thought that the toxin, a potent protein synthesis inhibitor, weakens the blood vessels in the rapidly growing lungs of infants. What happens next is not entirely clear, but probably subsequent exposure to stressors such as environmental tobacco smoke or other diseases prompts the development of full-fledged pulmonary hemorrhage.
The shiny, black mold grows only on water-soaked cellulose, which can include building materials such as acoustic ceiling tiles and gypsum board (drywall). Therefore, houses that are prone to flooding or that have leaky roofs or plumbing problems are far more likely than drier homes to harbor the mold. However, although S. atra is quite common in North America, it is unusual to find it growing inside a house precisely because of the water-logged condition necessary for its growth. Nevertheless, the mold was found in the homes of the sick children.
Dorr G. Dearborn, a pulmonary specialist at Rainbow Babies and Children's Hospital in Cleveland, Ohio, was the first to recognize the disturbingly high incidence of the condition back in 1994. From January 1993 to December 1994, there were 10 recognized cases of the disease, which, until that time, had not been diagnosed in humans in the United States; the condition was associated only with animals that had eaten moldy fodder. Dearborn is concerned that the condition, undiagnosed, kills a greater number of children than was previously suspected. A reexamination of Cuyahoga County, Ohio, coroners' cases of infant deaths over a three-year period revealed six cases that involved pulmonary bleeding, which, in retrospect, may have been attributable to the presence of S. atra. In addition, pulmonary hemosiderosis is not always readily recognizable and may manifest only subtle symptoms at first. While over 70 cases had been identified elsewhere in the United States as of July 1997, the disease appears to be mysteriously concentrated in a seven-zipcode cluster in east Cleveland, and no one is sure why.
The NIEHS and the CDC have established a joint grant for Dearborn to study the black mold, using infant mice as subjects. The mice will be exposed to the mold at 3-7 days of age and will be harvested days to weeks later to assess the state of their lungs. Dearborn will also study the effect of various stressors, such as cigarette smoke, on the spore-riddled lung tissue. It is hoped that this will lead to a clearer understanding of how the mold spores damage the lungs and cause hemorrhage, and how pulmonary hemosiderosis can be controlled and possibly prevented. The two agencies have contributed a total of $76,000 toward this research.
Case Western Reserve University has set up a page on the Internet at URL http://gcrc.meds.cwru.edu/stachy.htm that contains public information about the mold. The site includes a summary of the Cleveland outbreak of pulmonary hemosiderosis and describes symptoms of the illness, with a particular recommendation for parents to consult a doctor immediately if their infant develops noninjury-related nosebleeds. The site also contains a description of S. atra and tips for cleaning up the mold. The university suggests that large growths of mold should be inspected by the local health department, which can help assess the problem and ensure that the mold is indeed S. atra rather than one of the other, less insidious black molds that occur more commonly in homes. Also, large growths of S. atra should be cleaned up with the help of a professional abatement contractor, because even adults are not completely immune to the deleterious effects of the mold spores. Finally, the site lists a number of resources to contact for more information about S. atra and its effects.
Environmental Learning 2000
The National Environmental Education and Training Foundation (NEETF), based in Washington, DC, is a nonprofit organization whose objective is to spread "essential environmental knowledge" to all U.S. citizens. The foundation defines essential environmental knowledge as "knowledge about the environment that every individual should have in order to be healthy and prosperous." To achieve this mission, the NEETF developed and recently launched Environmental Learning 2000, a five-year enterprise that is intended to revolutionize the way environmental education is perceived and conducted in the United States. Says Kevin Coyle, president of the NEETF, "Environmental Learning 2000 offers a unique approach to link the environment with issues of critical national concern, such as rising health care costs, business competitiveness, potential threats to drinking water supplies, and improving science education in the schools."
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Menacing mold. Stachybotrys atra, a black mold, produces a toxin that can wreak havoc on the lungs of infants. |
Dorr G. DearbornEnvironmental Learning 2000 is a four-pronged effort that includes a number of different programs in the areas of environmental health, business and the environment, natural resources management, and educational excellence. The theme running through all the programs is the idea of trickle-down education; if society's leaders can be taught, they can then teach the public about the risks and concerns, the problems and importance of the environment in every human life. The program is largely targeted toward the professional community, particularly industries, health care providers, water treatment utilities, and educators.
Two Environmental Learning 2000 programs are aimed as much at actually improving environmental health as at educating people to its importance. The Environ-Med Program is designed to remedy the current dearth of knowledge among health care professionals regarding environmental health, specifically how to recognize, effectively treat, and prevent environmentally based illnesses. Environ-Med supports activities that will address environmental health training in medical and nursing schools, develop assessment and diagnostic tools for practicing health professionals, and convene the field's leaders on an annual basis. This program will also reach into the managed care arena, as well as pull in the media and the general public. The Water-Source Project, planned to last for three years, focuses on educating water utilities, community leaders, and government agencies on the advantages of source water protection (i.e., proactively protecting drinking water sources instead of relying on costly treatment plants). Foundation literature notes the exorbitant cost of ignorance and inaction: over $140 billion may be spent over the next 15 years on cleaning up water that could just as easily be kept from becoming polluted in the first place.
The Environmental Competitiveness Institute is a mentoring program in which larger companies that are running effective environmental health programs are matched with smaller companies that lack the resources necessary to develop such programs on their own. The larger companies share their experience and help their smaller partners implement environmental performance programs. Such programs, while benefiting the environment, also frequently lead to improved corporate profits through decreased operational costs.
Along with several public agencies, the NEETF sponsors National Public Lands Day. This annual event is held in communities across the United States, and volunteers from each community spend the day participating in local land and recreational improvements. It's an opportunity for the public to become more familiar with local resources while necessary but costly work is accomplished through volunteer labor.
The NEETF has a four-part approach to enhancing environmental education in U.S. schools. First is the Foundations for the Future Program. Through this program, national standards are being set to ensure that kids in grades K-12 receive a balanced environmental education that is based on sound science. NEETF studies have shown that adding environmental education to a school's curriculum boosts students' overall scholastic performance in math, science, and social studies by giving them a better groundwork for understanding many of the principles of those subjects. Second, the organization conducts research to identify ways in which environmental education can be used to address issues of national importance, such as education reform. Third, the foundation directs a national awards program that honors outstanding achievements in environmental education by individuals or corporate bodies. Finally, the foundation has established a policy program that will develop new ways to implement the mandates of the foundation's guiding-star legislation, the National Environmental Education Act of 1990.
Passive Smoke Linked to Abnormal HDL in Children
Environmental, or passive, cigarette smoke has been linked with a number of serious health problems in children including upper respiratory infections, chronic cough, asthma, chronic ear infections, and sudden infant death syndrome. Now it appears that exposure to environmental tobacco smoke may also cause children with abnormal cholesterol levels--already at risk for future heart disease--to be even more likely to develop the disease at some point.
A study published in the 2 September 1997 issue of Circulation showed that children who were exposed to environmental cigarette smoke at home had high-density lipoprotein (HDL) cholesterol levels that were as much as 10% lower than those of children who came from nonsmoking households. HDL cholesterol, frequently called "good" cholesterol, protects against heart attacks by culling fats from the bloodstream, which keeps the coronary arteries free of plaque buildup. Fortunately, the findings also suggest that a child's HDL level can be raised by 10% if the smoky environment is cleaned up. This rise is equal to or better than many other risk-reducing strategies such as increased exercise and lowered fat intake.
The study was conducted by Ellis J. Neufeld, director of clinical hematology at Boston Children's Hospital, and colleagues, who examined a group of 103 children aged 2-18. All of the children had come to the hospital for treatment of high cholesterol, and most of them had family members in the early stages of coronary disease. Neufeld says that his group originally sought to determine the extent to which patients followed the clinic's advice on leading a healthier lifestyle and what effect following such advice had on their cholesterol problems. But as the remarkable correlation between tobacco smoke exposure and HDL levels emerged, Neufeld and colleagues began to target that relationship as the basis of the study. Just over one-fourth of the children lived in households where some cigarette smoking was reported. It was unknown exactly how much smoke the children encountered in their homes, but one thing seemed clear: the children from smoking households had HDL levels averaging 38 milligrams per deciliter (mg/dl) of blood, compared to HDL levels averaging 43 mg/dl for children from nonsmoking households.
Because the study subjects all had some form of cholesterol abnormality, it is not possible to extrapolate the findings to all children. Neufeld says the next step will be to replicate the study with the goal of quantitating the amount of actual smoke exposure received by each study subject. One method for doing this might be to monitor each subject's urinary cotinine levels (cotinine, a metabolite of nicotine, is a biomarker of nicotine exposure). If exposure to cigarette smoke does indeed cause lowered blood HDL levels, then it could reasonably be expected that a rise in urine cotinine levels would correspond with a drop in blood HDL levels. Comparison of fluctuations in cotinine levels and blood HDL levels could therefore establish that a correlation exists between the occurrence of the two substances.
Cholesterol disorders are largely hereditary. Children who already have a cholesterol disorder can ill afford any reduction in their bodies' natural heart disease prevention mechanisms. When the child's parents smoke, the child is at even greater risk because smokers' offspring tend to become smokers themselves.
Since 1991, Neufeld says, the clinic has urged its young patients' parents to stop smoking. Or, he continues, if the parents are unable to stop smoking, they should at least smoke outside, rather than in a designated "smoking area" within the house. Indeed, according to a study published in the Environmental Journal in 1986, it takes approximately two weeks for the nicotine to clear out of the air in a room where people have smoked. Says Neufeld of parents who have cholesterol abnormalities of their own and who also smoke, "These parents are already at high risk in their own right. Getting them to stop smoking is extraordinarily important."
Growing Up Healthy
Statistics such as infant mortality rate have long shown that the United States is not protecting its children's health as successfully as many of the other major industrialized countries. This is cause for concern among many health professionals, particularly those at the National Institute of Child Health and Human Development (NICHD), one of the National Institutes of Health. Since 1962, the institute has aggressively sought to improve the health of the United States' children by sponsoring research focused on children and conducting educational programs for parents. Many of these endeavors have seen significant success.
For example, recent research sponsored by the NICHD has shown that many victims of sudden infant death syndrome (SIDS) possess abnormalities in their brain stems, giving doctors new ammunition to fight this leading cause of death among infants. In addition, the NICHD has recruited Tipper Gore as spokesperson for the SIDS "Back to Sleep" campaign, which teaches parents to avoid SIDS by always putting infants down to sleep on their backs. Such programs have been credited with reducing SIDS deaths in the United States by 30% between 1992 and 1995.
Information
about what the NICHD is doing to fight SIDS and other threats to children's health
is available from the NICHD home page at http://www.nichd.nih.gov.
Links on the home page lead to information specifically tailored for scientists,
the media, doctors, and parents on what is being done--and what should be done--to
ensure that children grow up to be healthy adults.
The Research link on the NICHD home page leads to information for scientists and health professionals who wish to take a larger role in protecting childhood and developmental health. Here, such users can find information on research grants offered by the NICHD and on NICHD-sponsored meetings. The Annual Report link on the Research page provides users with a list of all of the laboratories within the NICHD, a description of the work and recent accomplishments of each, and links to the home pages of certain laboratories. Under the Patients link, users can click on a specific diagnosis to see if the NICHD is currently conducting a clinical trial in that area.
Scientific publications available from the NICHD are listed under the Publications link on the home page. In addition to descriptions of various diseases and syndromes that affect children, reports on NICHD research programs, conference proceedings, state-of-the-science reports, and information packets on NICHD grants and contracts are among the free materials that may be ordered by following instructions on this page. Health professionals wishing to become even more intimately involved in the mission of the NICHD may also want to check the employment opportunities page, which can be found via the About NICHD link on the institute's home page.
Besides providing information for scientists, the NICHD home page is also a resource for parents who want to know more about protecting the health of their children. Links on the home page take parents to information on NICHD campaigns such as "Back to Sleep" and "Milk Matters," which stresses the importance of getting enough calcium. In addition, a discussion of why children should not be given adult medications is available under the Patients link on the home page. Here, the site also describes the Pediatric Pharmacology Research Network Unit, a resource for the study of how drugs work in children.
Last Update: January 8, 1997