Multipathway exposures were evaluated for residents of houses over a 10-day period following a crack and crevice application of a chlorpyrifs-based mulaion. Three multiroom houses with two adults each were treated. Air concentration, total deposition, and dislodgeble residue on horizontal surfaces were measured to assess potential respiratory, oral, and dermal exposures, respectively, in treated and untreated hg activity rooms. In addition, urine samples collected from the adults were analyzed for the primary metabolite of chlorpyrifos, 3,5,6-tichloropyridinol, to determine absorbed dose. The maximum chlorpyrifos air concentration observed was 2.3 pglm3, with air concentrations generally decreasing to levels ranging from 0.1 to 0.3 pg/m3 within 10 days. Carpet dislble residues, used to evaluate the amount of residues potentially transferred upon contact, were less than the analytical method limit ofquantitation (1.6 pg/m2). Hard plastic balls plaed in the homes on the day before application contained no detectable dislodgeable residues (<6.5 pg/m2). Ten-day cumulative non residues deposited on surfaces, as determined by deposition pads, were less than 2.3 pg/l00 cm2. Deposition samples firom all living area floors collected 2 hr after applicai ontained less than 9.9 pgl00 cm2. Therefore, contact with household surf and subsequent hand-to-mouth activity are not expected to significantly contribute to overall exposure. Estimated exposures to children, based on the passive dosimetry msurements, r from 0.26 to 2.1% of the no observed effect level for plasma cholinesterase depression. In addition, potential exposures to the adult residents, as indicated by the urinary 3,5,6-TCP biomonitoring, did not increase as a result of the application. Key wordk children's toys, chlorpyrifos, disodgeable residues, nondietary exposure and dose, partide deposition, pesticide application, pesticide residuas, semivolatile pesticide, surface wipes, uinary biomonitoring. Environ Healh Pepect 106:725-731 (1998). [Online 14 October 1998] hnp://ehpnetl. niehs.nih.gou doas/ 998/106p725-73lbyaXe/abstrabt hml Chlorpyrifos is used for structural, crack and crevice, and outdoor turf and perimeter treatments for the control of pests in the urban environment. Because of widespread urban and agricultural uses, numerous toxicity and exposure studies have been conducted over the past 30 years to ensure that chlorpyrifos-containing products are safe for both applicators and residents of the treated homes. However, few studies have evaluated potential multipathway exposures to adults and children following a crack and crevice treatment-the primary indoor use pattern for chlorpyrifos products. Moreover, few studies have been conducted in occupied multiroom homes.Previously, studies have been performed to assess exposures to occupants following broadcast and fogging treatments using chlorpyrifos (1)(2)(3)(4) Deposition pads. To measure total chlorpyrifos deposition onto nontarget horizontal surfaces, 100-cm2 denim cloth pads were placed on horizont...

Spinosad is a bacterially derived insect control agent consisting of two active compounds, spinosyns A and D. The objective of this paper is to describe the environmental fate of spinosad in aquatic systems. To this end, several studies performed to meet regulatory requirements are used to study the fate and degradation in individual environmental media. Specifically, investigations of abiotic (hydrolysis and photolysis) and biotic (aerobic and anaerobic aquatic) processes are described. Understanding developed from the laboratory-based studies has been tested and augmented by an outdoor microcosm study. Understanding of aquatic fate is a building block for a complete environmental safety assessment of spinosad products (Cleveland, C. B.; Mayes, M. A.; Cryer, S. A. Pest Manag. Sci. 2001, 58, 70-84). From individual investigations, the following understanding of dissipation emerges: (1) Aqueous photolysis of spinosad is rapid (observed half-lives of <1 up to 2 days in summer sunlight) and will be the primary route of degradation in aquatic systems exposed to sunlight. (2) Biotic transformations contribute to spinosad's dissipation, but less so than photolysis; they will be of primary importance only in the absence of light. (3) Spinosad partitions rapidly (within a few days) from water to organic matter and soil/sediment in aquatic systems but not so rapidly as to replace sunlight as the primary route of dissipation. (4) Abiotic hydrolysis is relatively unimportant compared to other dissipation routes, except under highly basic (artificial) conditions and even then observed half-lives are approximately 8 months. Degradation pathways are understood are follows: (1) Degradation primarily proceeds by loss of the forosamine sugar and reduction of the 13,14-bond on the macrolide ring under aqueous photolytic conditions. (2) Degradation to several other compounds occurs through biotic degradation. Degradation under anaerobic conditions primarily involves changes and substitutions in the rhamnose ring, eventually followed by complete loss of the rhamnose ring. Degradation under aerobic conditions was more extensive (to smaller compounds) with the loss of both the forosamine and rhamnose sugars to diketone spinosyn aglycon degradates. (3) Hydrolytic degradation involves loss of the forosamine sugar and water and reduction on the macrolide ring to a double bond at the 16,17-position.

No abstract

No abstract

dropwise, with 7 g (0.013 mol) of propionaldehyde in 25 ml of ether. The mixture was stirred overnight at room temperature and then worked up to give 3.2 g (38%), bp 87-91°( 12.5 mm), consisting of a mixture of cis and trans isomers. The trans isomer of l-(o-tolyl)-l-butene was separated by glc on column 1" and obtained as a colorless liquid: ir (liq) 1650 (C=C), 1600 (Ar), 1380 (C-CH3), 964 (tra/w-CH=CH), 744 cm™1 (1,2-disubstituted Ar); nmr (CCU) 1.10 (t, 3,