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AIRBORNEIndustrial Health CONCENTRATIONS 2011, 49, 703–713 OF ORGANOPHOSPHORUS PESTICIDES IN MANUFACTURING WORKPLACESOriginal Article703 Airborne Concentrations of Organophosphorus Pesticides in Korean Pesticide Manufacturing/ Formulation Workplaces Don-Hee HAN1 1Department of Occupational Health and Safety Engineering, Inje University, Gimhae, Gyeongnam-do 621-749, Republic of Korea Received May 23, 2011 and accepted August 30, 2011 Published online in J-STAGE October 20, 2011 Abstract: Pesticide manufacturing/formulation workers rather than farmers or applicators or people living with them are primarily exposed to organophosphorus pesticides (OPs). However, airborne concentrations in the workplace have rarely been determined. A total of 121 air sam- ples (personal or area sampling) were collected at 4 factories where chlorpyrifos, EPN, parathi- on, and phorate, were manufactured/formulated from March through July, 2007–2008. Samples were collected by the National Institute for Occupational Safety and Health (NIOSH) method and were analyzed by GC-MS. The geometric mean (GM) level of airborne chlorpyrifos was 0.17 mg/m3, 85% Korean Occupational Exposure Limit (KOEL) of 0.2 mg/m3, and at 95% con- fidence, airborne concentrations exceeded the KOEL 58.8% of the time or less, indicating that this concentration level was unacceptable according to exposure assessment using a LogNorm2®. However, compared with levels of TLV and/or PEL and/or WEL, the GM concentration levels of other OPs were remarkably low (range, 0.1–15.0%) and that these levels of concentrations to the other OPs were acceptable. The levels of airborne concentrations of OPs depended on isolation of the process; in other words, the levels depended on the extent to which the process was automated. The reason that the airborne concentration levels, except for those of chlorpy- rifos, were very much lower than expected may be attributable to the fact that there was not exposed to 100% toxic active ingredients in pesticide formulation workplaces because of the use of supplemental agents or additives to produce complete pesticides. This study is limited since there were seldom or neither any data of previous studies to be compared with the study results nor dermal exposure data. The results were used to revise KOELs for OPs in 2010. Key words: Organophosphorus pesticides (OPs), Chlorpyrifos, EPN, Parathion, Phorate, Pesticide formulation worker, Korean Occupational Exposure Limit (KOEL) Introduction humans is due to the inhibition of esterase. This results in the development of 3 or, possibly, 4 syndromes. Organophosphorus pesticides (OPs) are widely used The acute cholinergic syndrome and the intermediate in agriculture, horticulture, and veterinary medicine. syndrome are the results of inhibition of the enzyme They are frequently used around households for public acetylcholinesterase (AChE). Rhinorrhea and bronchor- hygiene and used in tropical countries to control disease rhea are prominent in OP poisoning and may interfere vectors. with respiratory function as may bronchoconstriction1). The fundamental toxicological activity of OPs in Constriction of the pupil diminishes vision in acute cho- linergic OP poisoning2). OPs mainly exert cholinergic effects on the gut, such as increased motility, abdominal E-mail: [email protected] cramping, and involuntary defecation. Effects on the 704 D-H HAN kidney are sometimes observed3), whereas developmen- all year round. After the production of a pesticide is tal toxicity and/or reproductive toxicity is sometimes completed, some parts of the manufacturing process observed2). The results of a previous study implied facilities are changed, and then used for manufacturing that OPs are neurotoxicants, and thus, neurobehavioural another OP. Unlike general industrial goods, a par- teratology is clearly an area of interest4). Within the ticular pesticide is generally produced for a few days sample of agricultural workers, a positive correlation or months to the volume of a year’s orders. Sampling was observed between urinary organophosphate metabo- therefore had to be performed only during the period lite levels and poor performance in neurobehavioural when the OPs of our interest were being produced, and tests5). Recently, epidemiologic evidence has suggested the sampling periods varied. Samples were collected a link between some OPs such as fonofos and phorate from March through July, 2007–2008. and cancer, but the evidence is insufficient to establish a causal relationship6–8). Sampling method The OPs banned owing to their toxicity by each gov- Personal air samples were preferentially collected ernment differ among countries9–13), thus, although the rather than area samples. However, in the case that use of some OPs such as parathion (granule form) and area sampling was more useful (for example, to identify phorate is banned in some countries, these OPs are still background levels of airborne contaminants and monitor manufactured and used in Korea. them), area sampling was performed24). Area sampling There are a number of studies on exposure to OPs, was also performed in areas where the workers moved but most subjects selected for the previous studies were swiftly and frequently: personal sampling is not likely to farmers5, 14–17), applicators18–20), children living in be effective in such cases. Each OP sampling, except households with farm workers, or the general residential for parathion, was conducted for the same worker or population21–23). Since few studies on exposure to OPs at the same site 3 times, once a day, for 3 consecutive in pesticide manufacturing/formulation workers have days. Parathion samples were collected once at the been reported, little is known about OP exposure among emulsifiable concentrate and once at the granule line. these workers, and even less is known about airborne Because workers in filling, labeling, taping, capping, concentrations in the workplace. These workers are and packing processes at the same indoor space were definitely directly exposed to OPs during the manufac- consecutively and directly exposed to pesticides, per- turing of pesticides, but airborne concentrations have sonal air sampling was performed in their case. Area been seldom assessed. Because the initial entry route sampling was conducted for workers who were likely of OPs is via inhalation, it is reasonable to assume that to be intermittently and indirectly exposed to pesticides determining airborne concentrations of OPs for manu- while addition of toxic active ingredients and mixing facturing/formulation workers should be a priority. of the ingredients in the hot hopper. However, workers The main goal of this study was to measure and who appeared to be exposed to very low levels of pesti- evaluate airborne concentrations of OPs in workplaces cides (in driving, shipping, etc.) were excluded from the where pesticides are manufactured and/or formulated, sampling. and to use these findings to revise Korean Occupational Personal samples were collected according to NIOSH Exposure Limits (KOELs) for OPs in Korea. method 5012 for EPN and NIOSH method 5600, Organophosphorus pesticides for other OPs25). A fil- Methods ter cassette holder for 25/37 mm (SKC, Inc., USA) for EPN, and a sorbent tube (OVS-2 tube: 13-mm quartz Workplaces investigated filter; XAD-2, 270 mg/140 mg, SKC, Inc., USA) con- Four factories manufacturing chlorpyrifos, EPN, tained in a holder for other OPs were placed in the parathion, and phorate were selected for this study. workers’ breathing zone and connected to a portable Chlorpyrifos, EPN, and phorate factories formulated battery-operated sampling pump, calibrated before and only the final products, whereas the parathion factory after use with a GilibratorTM flow meter (Sensidyne, produced both raw active ingredients and complete Inc., USA). Samples were obtained at a flow rate of products. There were 25 employees working at the 0.2–0.5 l/min for 360–400 min. Field blanks were col- chlorpyrifos factory, 8 at EPN, 18 at parathion, and 5 at lected in a similar manner, except that no air was pulled phorate. through the sample. Samplers for area sampling were placed in the area as close as possible to the breathing Sampling duration zone of the workers. Sampling was performed using One of the characteristics of pesticide production is the same abovementioned method for personal sampling. that the same product (a pesticide) is not manufactured The samples were stored in an icebox below 4°C after Industrial Health 2011, 49, 703–713 AIRBORNE CONCENTRATIONS OF ORGANOPHOSPHORUS PESTICIDES IN MANUFACTURING WORKPLACES 705 Table 1. GC-MS conditions for OP analysis Condition Parameter EPN Chlorpyrifos Parathion Phorate Carrier gas He at 1 ml/min 100°C (1 min), ramped at 150°C (1 min), ramped at 140°C (1 min), ramped at 100°C (1 min), ramped at Oven 15°C/min to 295°C, post run 15°C/min to 235°C, post run 20°C/min to 260°C, post run 15°C/min to 220°C, post run temperature 300°C (5 min) 300°C (5 min) 300°C (5 min) 300°C (5 min) Injector type Split mode (1:5) Split mode (1:10) Injector temperature 300°C 280°C Selected ion, m/z 159, 167, 185, 323 197, 258, 314 97, 109, 139, 188, 291 75, 121, 188, 260 use, and then frozen until analysis in the laboratory. Results The samples were analyzed at least 10 d after the sam- pling was completed. General pesticide-manufacturing processes In pesticide manufacturing, an active ingredient is Analytical procedure first synthesized in a chemical factory. Next, a formula- EPN was extracted from samples by using 15 ml tor mixes the active ingredient with a carrier (for liquid isooctane, according to NIOSH method 5012, and other pesticide) or with inert powders or dry fertilizers (for OPs were extracted using 2 ml of 90% toluene/10% dust pesticide), then bottles or packages it. The active acetone solution, according to NIOSH method 560025). ingredient kills the pests, while the inert ingredients Analysis was performed using a gas chromatograph facilitate spraying and coating the target plant; they can (GC) (Agilent 6890)-mass spectrometer (Agilent 5973N) also contribute other advantages that are not conferred system with an electron impact ionization operating in by the active ingredient alone.