Licensed pesticide applicators who used chlorinated pesticides for more than 100 days in their lifetime were at greater risk of diabetes, according to researchers from the National Institutes of Health (NIH). The associations between specific pesticides and incident diabetes ranged from a 20% to a 200% increase in risk, said the scientists with NIH's National Institute of Environmental Health Sciences (NIEHS) and the National Cancer Institute (NCI).
"The results suggest that pesticides may be a contributing factor for diabetes along with known risk factors, such as obesity, lack of exercise, and having a family history of diabetes," said Dale Sandler, Ph.D., chief of the Epidemiology Branch at the NIEHS and coauthor of the paper. "Although the amount of diabetes explained by pesticides is small, these new findings may extend beyond the pesticide applicators in the study," Sandler said.
Some of the pesticides used by these workers are also used by the general population, though the strength and formulation may vary. Other insecticides in this study are no longer available on the market; however, these chemicals persist in the environment and measurable levels may still be detectable in the general population and in food products. For example, chlordane, which was used to treat homes for termites, has not been used since 1988, but can remain in treated homes for many decades. More than half of those studied in the National Health and Nutrition Examination Survey in 1999–2002 had measurable evidence of chlordane exposure.
"This is not cause for alarm, since there is no evidence of health effects at such very low levels of exposure," Sandler said.
Overall, pesticide applicators in the highest category of lifetime days of use of any pesticide had a small increase in risk for diabetes (17%) compared with those in the lowest pesticide use category (0–64 lifetime days). New cases of diabetes were reported by 3.4% of those in the lowest pesticide use category compared with 4.6% of those in the highest category. Risks were greater when users of specific pesticides were compared with applicators who never applied that chemical. For example, the strongest relationship was found for a chemical called trichlorfon, with an 85% increase in risk for frequent and infrequent users and nearly a 250% increase for those who used it more than 10 times. In this group, 8.5% reported a new diagnosis of diabetes compared with 3.4% of those who never used this chemical. Trichlorfon is an organophosphate insecticide classified as a general-use pesticide that is moderately toxic. Previously used to control cockroaches, crickets, bedbugs, fleas, flies, and ticks, it is currently used mostly in turf applications, such as maintaining golf courses.
"This is one of the largest studies looking at the potential effects of pesticides on diabetes incidence in adults," said Freya Kamel, Ph.D., a researcher in the intramural program at NIEHS and coauthor of the paper appearing in the May issue of the American Journal of Epidemiology. "It clearly shows that cumulative lifetime exposure is important and not just recent exposure."
Previous cross-sectional studies have used serum samples to show an association between diabetes and some pesticides. Diabetes occurs when the body fails to produce enough insulin to regulate blood sugar levels or when tissues stop responding to insulin. Nearly 21 million Americans have diabetes. The cause of diabetes continues to be a mystery, although genetics and environmental factors such as obesity and lack of exercise appear to play roles.
The 31,787 applicators in this study included those who completed an enrollment survey about lifetime exposure levels, were free of diabetes at enrollment, and updated their medical records during a five-year follow-up phone interview. Among these, 1,171 reported a diagnosis of diabetes in the follow-up interview. The majority of study participants were non-Hispanic white men.
Researchers compared the pesticide use and other potential risk factors reported by the 1,171 applicators who developed diabetes since enrolling in the study to those who did not develop diabetes. Among the 50 different pesticides the researchers looked at, they found seven specific pesticides—aldrin, chlordane, heptachlor, dichlorvos, trichlorfon, alachlor, and cynazine—that increased the likelihood of diabetes among study participants who had ever been exposed to any of these pesticides, and an even greater risk as cumulative days of lifetime exposure increased.
All seven pesticides are chlorinated compounds, including two herbicides, three organochlorine insecticides, and two organophosphate pesticides.
"The fact that all seven of these pesticides are chlorinated provides us with an important clue for further research," said Kamel. Previous studies found that organochlorine insecticides such as chlordane were associated with diabetes or insulin levels. The new study shows that other types of chlorinated pesticides, including some organophosphate insecticides and herbicides, are also associated with diabetes. The researchers also found that study participants who reported mixing herbicides in the military had increased odds of diabetes compared with non-military participants.
Why Diesel Particulates Cause Cardiovascular Disease
In a dissertation defended at Ume? University, Sweden, on June 5, H?kan T?rnqvist maps previously unknown mechanisms that may explain why air pollution in the form of particulates causes heart attacks, stroke, and increasing mortality.
Particulates in diesel exhaust are a substantial cause of the negative health effects traced to air pollution, above all in traffic environments. Diesel exhaust contains a number of extremely tiny particles about 1/10,000 mm in diameter, with chemical compounds bound to the surface that have been suggested to lie behind the ability of these particles to cause harmful health effects.
Individuals with lung or heart disease are especially vulnerable and are impacted most negatively during periods with high levels of air pollution. In his dissertation, H?kan T?rnqvist studied the effects of diesel exhaust on healthy individuals and respective patient groups with chronic obstructive lung disease (COL) and coronary disease with atherosclerosis in the coronary artery.
The aim of the studies in the dissertation was to use controlled exposure studies to try to elucidate the mechanisms that explain why diesel exhaust particulates in polluted air cause increased morbidity in both lung and heart diseases. The studies were carried out in an exposure chamber, where the individuals were exposed for one hour to diesel exhaust with a particulate concentration of about 300 µg/m3 and filtered air. The two exposures were in random order, so the individuals served as their own controls.
The dissertation work studied whether exposure to diesel exhaust would lead to a deterioration of the lung function and increased inflammation of the airways as measured by induced sputum (coughing samples) in patients with moderately severe but stable COL. Analysis of the cough samples could not reveal any increase in inflammation of the airways, nor was there any deterioration of the lung function. Studies of the these same patients were also used to determine whether exposure to diesel exhaust can lead to increased general inflammation, can impact the capacity of the blood to coagulate, or can cause damage to the lung epithelia as measured in the blood. No general increase in blood coagulation or signs of increased inflammation in the blood could be found.
The thesis also addressed the question of whether exposure to diesel exhaust can affect the vascular function in a group of healthy individuals two and six hours after exposure. In this group, exposure to diesel exhaust decreased two important and complementary blood-vessel functions: the regulation of the width of the blood vessels and the body’s own ability to dissolve blood clots (fibrinolysis). What’s more, the study illuminated the late course of events involved in the blood-vessel effects triggered by diesel exhaust in healthy individuals in the test. As much as 24 hours after their exposure to exhaust, the capacity of their blood vessels to expand was disturbed. Moreover, there were signs of systemic inflammation, measured as an increase in inflammatory markers in the blood.
The final study in the dissertation targeted individuals with clinically fully stable coronary artery disease. The issue was whether exposure to diesel exhaust can affect the heart, decrease vessel mobility, and hamper the capacity to dissolve blood clots. A lowered capacity to dissolve blood clots was observed, together with an impaired ability of blood vessels to expand. The most important finding, however, was that after exposure to diesel exhaust, patients evinced EKG signs that were consistent with a shortage of oxygen in the heart muscle. This effect was general, that is, not limited to any particular blood vessel in the heart, and it was observed despite the fact that the patients were fully stable in their coronary artery disease and were under optimal medical treatment.
The dissertation clarifies previously unknown mechanisms that can explain why air pollution in particulate form causes heart attacks, stroke, and increased mortality. It shows that diesel exhaust causes a rapid deterioration of blood vessel function that persists as long as 24 hours after exposure. The EKG findings in heart patients indicate acute heart effects that are consistent with increased risk of heart attack in connection with exposure to traffic.
Lead Leaching and Faucet Corrosion in PVC Plumbing
Scientists in Virginia are reporting that home plumbing systems constructed with polyvinyl chloride (PVC) plastic pipes may be more susceptible to leaching of lead and copper into drinking water than other types of piping—especially when PVC systems include brass fixtures and pipefittings.
Marc Edwards and colleagues point out that more water purification plants in the United States are using chloramine to treat water. At the same time, builders are plumbing more houses with plastic pipe, rather than copper, to cut costs. Past studies have found that ammonia formed in chloramine-treated water can trigger a series of events that corrode brass faucet components and connectors commonly used in PVC plumbing systems. Corrosion of brass (made with copper, zinc, and lead) releases those metals into water pipes and makes faucets prone to failure.
In the new study, researchers sampled water from polyvinyl chloride (PVC), copper, lead, and other pipe material under a range of experimental conditions. They found that corrosive conditions were often worst in plastic pipes, which could be expected to cause higher metal leaching of zinc and lead from brass faucets used in homes and buildings.
Bisphenol A: Controversy Over Widely Used Plastics Spurs Product Changes, Regulatory Debate
Widely used in consumer products, including baby bottles and beverage bottles, BPA has come under increasing scrutiny by Congress, regulators in the United States and abroad, the news media, and other groups over its allegedly harmful health effects.
Written by C&EN Associate Editor Britt Erickson, the story points out that retailers and manufacturers alike are not waiting for scientists to settle the unknowns about BPA, which can have estrogen-like biological effects. Instead, they have been pulling BPA products from store shelves or abandoning its use altogether. Consumers also are avoiding products packaged in containers made with BPA.
More than two billion pounds of BPA are used annually in the United States. Although a growing number of studies suggest that low-level exposure to the chemical can cause cancer, obesity, and other health problems, the plastics industry and federal regulatory agencies insist that the chemical is safe, the article states. Erickson described how Congress entered the fray by launching an investigation into the use of BPA in baby bottles.
Is Tap Water Safe for Expectant Mothers?
This finding, based on an analysis of nearly 400,000 infants in Taiwan, is the first that links by-products of water chlorination to three specific birth defects. Water chlorination is a widely used and efficient method to disinfect drinking water and reduce the occurrence of waterborne diseases. However, numerous studies have revealed the presence of many chlorination by-products in the water. Recent research suggests that prenatal exposure to these by-products may increase the risk of birth defects.
A research team led by Jouni Jaakkola from the Institute of Occupational and Environmental Medicine, University of Birmingham, United Kingdom, gathered data on almost 400,000 infants born in Taiwan. The researchers used statistical analyses to see if drinking tap water containing high, medium, or low levels of chlorination by-products increased the risk of 11 common birth defects.
Although the researchers found no direct link between the prevalence of any birth defect and the level of exposure, their calculations revealed that exposure to high levels of by-products substantially increased the risk of three common defects: ventricular septal defects (holes in the heart), cleft palate, and anencephalus (where neural development fails, resulting in the absence of a major portion of the brain, skull, and scalp).
Exposure to total trihalomethanes above 20 ?g/L was associated with an increased risk of 50% to 100% compared with levels below 5 ?g/L. These results were corroborated by additional analyses, using pooled data from a number of similar studies.
"The biological mechanism for how these disinfection by-products may cause defects are still unknown," says Jaakkola. "However, our findings don't just add to the evidence that water chlorination may cause birth defects, but suggest that exposure to chlorination by-products may be responsible (for) some specific and common defects. Whilst the benefits of water chlorination are quite evident, more research needs to be carried out to determine these side-effects."
OSHA Cites Two Employers in New York Scaffold Collapse
OSHA has cited two New York City employers for alleged violations of federal workplace safety standards in connection with a Dec. 7, 2007, scaffold collapse at 265 E. 66th St. in Manhattan. Two window washers fell 47 stories when their scaffold platform detached from the permanent window washing rig attached to the building's roof.
Cited were City Wide Window Cleaning LLC, the Richmond Hill, N.Y., window cleaning service that employed the window cleaners and operated the scaffold, and Tractel Inc., the Long Island City, N.Y., company that serviced the scaffold prior to the accident. The citations address equipment failure, lack of fall protection, and lack of employee training.
OSHA's inspection found that the crimps used to secure the platform's hoist ropes were improperly installed by Tractel and, as a result, unable to support the scaffold's load. Neither Tractel nor City Wide had inspected the scaffold to determine if the crimps had been correctly installed and to see if the scaffold could support its load.
The two employees lacked fall protection, as they were not wearing safety harnesses and lifelines tied off to independent anchorage points and had not been trained in fall-protection measures. They also had not been trained in the inspection and operation of the scaffold, emergency procedures, and hazards associated with their work.
"These men lacked the knowledge and ability to protect themselves against falls and other hazards," said Richard Mendelson, OSHA's area director in Manhattan. "Proper inspection and maintenance of the scaffold and its components could have prevented this accident, while effective employee training and use of fall protection would have stopped any fall."
City Wide Window Cleaning has been issued five serious citations for the lack of fall protection, training, inspections, and for the lack of a vertical lifeline. The company faces $24,000 in proposed penalties. Tractel has been issued three serious citations, with $21,000 in proposed penalties, for improper installation of the crimps, the crimps' failure to support the scaffold's load, and not inspecting the crimps. A serious citation is issued when death or serious physical harm is likely to result from a hazard about which the employer knew or should have known.
"We will be sharing our findings with the New York City Department of Buildings and the New York State Department of Labor, which regulates this type of window-washing equipment, to help prevent such an accident from occurring again," said Mendelson.
OSHA Fines Construction Contractor $72,000 for Repeat Safety Violations
OSHA has cited R. K. Wallace Construction Inc., doing business as Wallace Steel Erectors, with three repeat safety violations and proposed penalties totaling $72,000 for allegedly failing to protect employees from fall hazards at its Covington, La., worksite.
"OSHA's regulations specifically state that any employee working upwards of 15 to 30 feet, while performing steel erection, must wear a harness," said Dean McDaniel, OSHA's regional administrator in Dallas. "No worksite should fail to protect employees from the hazards of falling. It is fortunate that no one was injured."
OSHA's area office in Baton Rouge, La., began an inspection March 19 at the company's worksite on Highway 1057 in Covington. The investigation found that the company failed to provide employees with fall-hazard equipment while performing steel-erection activities, and did not provide training and instruction to employees exposed to fall hazards. The company also failed to ensure that the scaffold platform used to lift employees by a rough terrain forklift was attached to the forks of the lift. A repeat violation is defined as a violation that previously was cited where, upon re-inspection, a substantially similar violation is found.
OSHA Cites North East Linen for Multiple Violations After Double Fatality
OSHA has cited North East Linen for multiple alleged safety and health violations after a double fatality at the company's Linden, N.J., facility.
OSHA initiated its investigation on Dec. 1, 2007, following the fatal accident. Two employees, who were cleaning a wastewater tank, were discovered at the bottom of the tank, which was oxygen-deficient and contained hazardous chemicals. The investigation resulted in 1 willful, 12 serious, and 2 other-than-serious violations.
"North East Linen did not take the appropriate steps to train its employees about potential hazards and to ensure its employees did not enter the wastewater tank, which led to this tragedy," says Robert D. Kulick, director of OSHA's Avenel, N.J., area office.
The company was cited for a willful violation for failing to provide hazard communication training. The serious citations include North East Linen's failure to provide adequate means of egress; to take effective measures to prevent employees from entering the wastewater tank; to lock out, or prevent accidental start-up of, equipment; to determine the presence and quantity of asbestos-containing material and not labeling the material; to close unused openings on an electrical panel; and to provide other necessary training.
"This horrible tragedy underscores the need for all employers to implement effective safety and health management systems," said Louis Ricca Jr., acting administrator for OSHA's New York region. "It also reinforces the need for employers to provide their employees with appropriate training, direction, personal protective equipment, and engineering controls, particularly when working in and around confined spaces."
OSHA defines a willful violation as one committed with plain indifference to or intentional disregard for employee safety and health. A serious citation is issued when death or serious physical harm is likely to result from a hazard about which the employer knew or should have known. The agency is proposing a total of $79,250 in fines for the combined violations.
Paper Manufacturer Faces 35 OSHA Citations Following Employee Death
OSHA has cited Brownville Specialty Paper Products Inc. for 35 alleged willful and serious violations of safety standards, following the death of an employee at its 1 Bridge St. plant in Brownville, N.Y.
The employee was fatally crushed on Dec. 5, 2007, by two large rolls of paper, weighing approximately 2,500 pounds, that rolled out of a rewinding machine. OSHA's inspection found that the machine's barrier guard was not interlocked with its drive mechanism to prevent the rolls from being ejected during rewinding operations, and the company knew of the hazard but did not correct it.
"This accident could have been prevented had this machine been properly guarded against this hazard," said Christopher Adams, OSHA's area director in Syracuse. "This case illustrates in the starkest possible terms why effective safeguards are necessary to prevent death and injury on the job."
OSHA has issued Brownville Specialty Paper Products one willful citation, carrying a $49,000 proposed fine, for the unguarded rewinding machine. OSHA defines a willful violation as one committed with plain indifference to or intentional disregard for employee safety and health.
OSHA's inspection also identified hazards involving blocked and obstructed emergency exit routes; fall hazards from unguarded stairways and work platforms, ladder deficiencies, lack of safety belts and lifelines, and an emergency exit opening onto an unguarded 30-foot-high landing; various unguarded moving machine parts; improper compressed gas storage; uninspected lifting equipment; several electrical hazards; respirator safety deficiencies; inadequate hearing protection; no emergency response plan and training for liquid chlorine spills; lack of training for employees entering confined spaces; unlabeled steam pipes and chlorine lines; and incomplete energy control procedures to prevent the unintended startup of machinery.
These conditions resulted in OSHA issuing the company 34 serious citations, with an additional $67,250 in proposed fines. A serious citation is issued when death or serious physical harm is likely to result from a hazard about which the employer knew or should have known. In all, the company faces a total of $116,250 in fines for the willful and serious citations.
