Malathion showed the lowest activity (LC50, 4.96mgmL-1) followed by in methomyl (3.88 mgmL-1), spinosad (3.69 mgmL-1), bifenthrin (2.58mgmL-1), l-cyhalothrin (2.42mgmL-1) and trichlorfon
(2.38mgmL-1) against susceptible strain of B.
All samples were found to be below the LODs for the analyzed compounds: mevinphos, dimethoate, parathion methyl, malathion, phosalone, trichlorfon
, phorate, parathion ethyl, azinphos methyl, azinphos ethyl, fenchlorphos, diazinon, and fenthion.
Fenthion (98% pure), fenthion sulfoxide (99%), fenthion sulfone (99%), fensulfothion (98%), fenitrothion (98%), trichlorfon
(98%), malathion (99%), and EPN (ethyl p-nitrophenyl benzenethiophosphonate, 98%) were purchased from Wako Pure Chemical Industries, Ltd.
Historically, eradication programs have used insecticidal control methods that follow the pattern of pesticide use in North America, beginning with Paris green in the late 1800s, lead arsenate during the first half of the twentieth century, DDT in the post-World War II era, and then carbaryl and trichlorfon
until the late 1980s (1).
Brain hypoplasia caused by exposure to trichlorfon
and dichlorvos during development can be ascribed to DNA alkylation damage and inhibition of DNA alkyltransferase repair.
Models were adjusted for age at enrollment (< 40, 40-49, 50-59, [greater than or equal to] 60 years), sex, education ([less than or equal to] high school graduate, > high school graduate), smoking (by pack-years: never, [less than or equal to] 14, > 14), alcohol consumption during the last 12 months (yes/no), family history of cancer (yes/no), year at enrollment, state of residence (Iowa/North Carolina), and the five pesticides most highly correlated with carbofuran use [permethrin (crop), S-ethyl dipropylthiocarbamate (EPTC), chlorpyrifos, fonofos, and trichlorfon
: never, low, high exposure].
Organophosphorus pesticides (n = 56) Acephate Anilofos Bromophos-ethyl Bromophos-methyl Butamifos Chlorpyrifos Chlorpyrifos-methyl Cyanofenphos Cyanophos Diazinon Dichlofenthion Dichlorvos Dimethoate Dioxabenzofos Disulfoton EPN Edifenphos Ethion Ethoprophos Fenamiphos Fenchlorphos Fenitrothion Fenitrothion oxon Fensulfothion Fenthion Glyphosate Iprobenfos Isofenphos Isoxathion Leptophos Malathion Mecarbam Methamidophos Methidathion Methyl-parathion Monocrotophos Parathion Phenthoate Phorate Phosalone Phosmet Piperophos Pirimiphos-methyl Profenofos Propaphos Prothiofos Prothiofos oxon Pyridaphenthion Quinalphos Terbufos Tetrachlorvinphos Thiometon Tolclofos-methyl Tolclofos-methyl oxon Trichlorfon
(e) Includes chlorpyrifos, coumaphos, diazinon, dichlorvis, fonofos, malathion, parathion, phorate, terbufos, and trichlorfon
. (f) Use of chemical by father before child's birth.
(d) Fewer than five cases used aluminum phosphide, coumaphos, dieldrin, trichlorfon
, or ziram.
We selected four additional pesticides (chlorpyrifos, trichlorfon
, propargite, dicofol) that were not named on the CADPR Groundwater Protection List but were identified by other states as being a concern to groundwater because of their high runoff or leaching potential, which was also based on their solubility, adsorption, or half-life (Cook et al.
Of the eight OP pesticides remaining in the residential market and considered in the 2006 cumulative risk assessment (i.e., acephate, bensulide, dichlorvos, disulfoton, malathion, naled, tetrachlorvinphos, trichlorfon
), five form DM metabolites, one forms DE metabolites, and two do not form any DAP metabolites.
Because of statistical power limitations, we excluded the 10 pesticides with < 10% prevalence among the cases (trichlorfon
, ziram, aluminum phosphide, ethylene dibromide, maneb/mancozeb, chlorothalonil, carbon tetrachloride/carbon disulfide, dieldrin, aldicarb, and2,4,5-trichlorophenoxypropionic acid), leaving 39 available for analysis.