Bibliography Tag: paraquat

Rappazzo et al., 2018

Rappazzo, K. M., Warren, J. L., Davalos, A. D., Meyer, R. E., Sanders, A. P., Brownstein, N. C., & Luben, T. J.; “Maternal residential exposure to specific agricultural pesticide active ingredients and birth defects in a 2003-2005 North Carolina birth cohort;” Birth Defects Research, 2018; DOI: 10.1002/bdr2.1448.


BACKGROUND: Previously we observed elevated odds ratios (ORs) for total pesticide exposure and 10 birth defects: three congenital heart defects and structural defects affecting the gastrointestinal, genitourinary and musculoskeletal systems. This analysis examines association of those defects with exposure to seven commonly applied pesticide active ingredients.

METHODS: Cases were live-born singleton infants from the North Carolina Birth Defects Monitoring Program linked to birth records for 2003-2005; noncases served as controls (total n = 304,906). Pesticide active ingredient exposure was assigned using a previously constructed metric based on crops within 500 m of residence, dates of pregnancy, and likely chemical application dates for each pesticide-crop combination. ORs (95% CI) were estimated with logistic regression for categories of exposure compared to unexposed. Models were adjusted for maternal race/ethnicity, age at delivery, education, marital status, and smoking status.

RESULTS: Associations varied by birth defect and pesticide combinations. For example, hypospadias was positively associated with exposures to 2,4-D (OR50th to <90th percentile : 1.39 [1.18, 1.64]), mepiquat (OR50th to <90th percentile : 1.10 [0.90, 1.34]), paraquat (OR50th to <90th : 1.14 [0.93, 1.39]), and pendimethalin (OR50th to <90th : 1.21 [1.01, 1.44]), but not S-metolachlor (OR50th to <90th : 1.00 [0.81, 1.22]). Whereas atrial septal defects were positively associated with higher levels of exposure to glyphosate, cyhalothrin, S-metolachlor, mepiquat, and pendimethalin (ORs ranged from 1.22 to 1.35 for 50th to <90th exposures, and 1.72 to 2.09 for >90th exposures); associations with paraquat were null or inconsistent (OR 50th to <90th: 1.05 (0.87, 1.27).

CONCLUSION: Our results suggest differing patterns of association for birth defects with residential exposure to seven pesticide active ingredients in North Carolina.

Costello et al., 2009

Costello S, Cockburn M, Bronstein J, Zhang X, Ritz B; “Parkinson’s disease and residential exposure to maneb and paraquat from agricultural applications in the central valley of California.” American Journal of Epidemiology. 2009 Apr 15;169(8):919-26. DOI: 10.1093/aje/kwp006.
Evidence from animal and cell models suggests that pesticides cause a neurodegenerative process leading to Parkinson’s disease (PD). Human data are insufficient to support this claim for any specific pesticide, largely because of challenges in exposure assessment. The authors developed and validated an exposure assessment tool based on geographic information systems that integrated information from California Pesticide Use Reports and land-use maps to estimate historical exposure to agricultural pesticides in the residential environment. In 1998-2007, the authors enrolled 368 incident PD cases and 341 population controls from the Central Valley of California in a case-control study. They generated estimates for maneb and paraquat exposures incurred between 1974 and 1999. Exposure to both pesticides within 500 m of the home increased PD risk by 75% (95% confidence interval (CI): 1.13, 2.73). Persons aged < or =60 years at the time of diagnosis were at much higher risk when exposed to either maneb or paraquat alone (odds ratio = 2.27, 95% CI: 0.91, 5.70) or to both pesticides in combination (odds ratio = 4.17, 95% CI: 1.15, 15.16) in 1974-1989. This study provides evidence that exposure to a combination of maneb and paraquat increases PD risk, particularly in younger subjects and/or when exposure occurs at younger ages. FULL TEXT

Almeida et al., 2017

Almeida, L. L., Teixeira, A. A. C., Soares, A. F., Cunha, F. M. D., Silva, V. A. D. Junior, Vieira Filho, L. D., & Wanderley-Teixeira, V.; “Effects of melatonin in rats in the initial third stage of pregnancy exposed to sub-lethal doses of herbicides;” Acta Histochemica, 2017, 119(3), 220-227; DOI: 10.1016/j.acthis.2017.01.003.


Exposure to the herbicides Paraquat (PQ) and Roundup((R)) may cause cell lesions due to an increase in oxidative stress levels in different biological systems, even in the reproductive system.

OBJECTIVE: Evaluate the possible changes in reproductive parameters and hepatic, as well as its prevention by simultaneous application of melatonin.

METHODS: Thirty-five female rats at the age of 3 months were divided into seven groups: three groups exposed to sub-lethal doses of the herbicides PQ (50mg/kg) and Roundup((R)) (500mg/kg) (n=5, G2, G3 and G4); three groups exposed to herbicides and simultaneous treatment with 10mg/kg of Melatonin (n=5, G5, G6 and G7) and control group (n=5, G1) from the first to the seventh day of pregnancy. On the seventh day of pregnancy, the rats were anesthetized and euthanized, followed by laparotomy to remove their reproductive tissues and liver. Body and ovary weights were taken and the number of implantation sites, corpora lutea, preimplantation losses, implantation rates were counted and histopathology of the implantation sites, morphometry of the surface and glandular epithelia of endometrium and hepatic oxidative stress were undertaken.

RESULTS: The present study shows the decrease in body and ovary weight, decrease in the number of implantation sites, implantation rate, in the total number of corpora lutea and increase of preimplantation percentages were observed when compared to the G1: Fig. 1 and Table 1, (p>0.001 ANOVA/Tukey). The histopathological analysis of the implantation sites showed a disorder of the cytotrophoblast and cell degeneration within the blastocyst cavity in Fig. 4. Morphometry revealed a reduction in surface and glandular epithelia and in the diameter of the endometrial glands (Table 2; p>0.05 ANOVA/Tukey), whereas in liver, serum levels of thiobarbituric acid reactive substances (TBARS) were found to be significantly elevated (Fig. 2; p>0.001; p>0.05 ANOVA/Tukey), and serum level of reduced glutathione (GSH) was significantly lower (Fig. 3; p>0.001 ANOVA/Tukey). However, treatments with melatonin exhibited improvements in reproductive parameters, as well as reduced lesions in the implantation sites (Fig. 4.) and in serum levels TBARS (Fig. 2; p>0.001 ANOVA/Tukey), serum levels GSH (Fig. 3; p>0.001; p>0.05 ANOVA/Tukey).

CONCLUSIONS: These results reveal that melatonin is a protective agent against experimentally induced maternal/embryo toxicity with herbicides and favoring normalization of reproductive parameters and hepatic.


Alexander et al., 2017

Alexander, M., Koutros, S., Bonner, M. R., Barry, K. H., Alavanja, M. C. R., Andreotti, G., Byun, H. M., Chen, L., Beane Freeman, L. E., Hofmann, J. N., Kamel, F., Moore, L. E., Baccarelli, A., & Rusiecki, J.; “Pesticide use and LINE-1 methylation among male private pesticide applicators in the Agricultural Health Study;” Environ Epigenet, 2017, 3(2), dvx005; DOI: 10.1093/eep/dvx005.


Cancer risk may be associated with DNA methylation (DNAm) levels in Long Interspersed Nucleotide Element 1 (LINE-1), a surrogate for global DNAm. Exposure to certain pesticides may increase risk of particular cancers, perhaps mediated in part through global DNAm alterations. To date, human data on pesticide exposure and global DNAm alterations are limited. The goal of this study was to evaluate alterations of LINE-1 DNAm by pesticides in a variety of classes. Data from 596 cancer-free male participants enrolled in the Agricultural Health Study (AHS) were used to examine associations between use of 57 pesticides and LINE-1 DNAm measured via Pyrosequencing in peripheral blood leucocytes. Participants provided information on pesticide use at three contacts between 1993 and 2010. Associations of ever/never pesticide use and lifetime days of application (years of use x days per year) and LINE-1 DNAm level were assessed using linear regression, adjusting for potential confounders (race, age at blood draw, and frequency of drinking alcohol) and other moderately correlated pesticides. After adjustment, ever application of 10 pesticides was positively associated and ever application of eight pesticides was negatively associated with LINE-1 DNAm. In dose-response analyses, increases in five pesticides (imazethapyr, fenthion, EPTC, butylate, and heptachlor) were associated with increasing LINE-1 DNAm (ptrend < 0.05) and increases in three pesticides (carbaryl, chlordane, and paraquat) were associated with decreasing LINE-1 DNAm (ptrend < 0.05). This study provides some mechanistic insight into the pesticide-cancer relationship, which may be mediated in part by epigenetics. FULL TEXT

Griffin et al., 2010

Griffin, James L., Boudreaux, Joseph M., & Miller, Donnie K.; “Herbicides As Harvest Aids;” Weed Science, 2017, 58(3), 355-358; DOI: 10.1614/ws-09-108.1.


Herbicides used as harvest aids are applied at crop maturity to desiccate weed and crop foliage. Weeds present in the harvested crop can increase moisture content and foreign material, reducing grade and market price. Weeds can also delay the harvest operation and reduce harvest efficiency. Glyphosate can be used to desiccate weeds in glyphosate-resistant crops without concern for crop injury. Carfentrazone and pyraflufen-ethyl used as harvest aids can be effective in desiccating broadleaf weeds in corn and soybean. Paraquat, although effective on grass and broadleaf weeds when applied late season, can cause significant crop injury if applied too early. With expanded production of early maturing soybean cultivars in the mid-South (Arkansas, Louisiana, Mississippi, Missouri bootheel, and west Tennessee), presence of green stems, green pods, or green leaf retention, or combinations of these at harvest has increased. Interest in harvest aids has shifted to use as a crop desiccant. Paraquat also is an effective soybean desiccant, but application timing differs for indeterminate and determinate cultivars. Paraquat applied after soybean seed reached physiological maturity reduced number of green stems, pods, and retained green leaves present, allowing harvest to proceed 1 to 2 wk earlier than nontreated soybean. Seed moisture, foreign material, and seed damage also were reduced when paraquat was applied. FULL TEXT

Kongtip et al., 2017

Kongtip, Pornpimol, Nankongnab, Noppanun, Phupancharoensuk, Ratanavadee, Palarach, Chonlada, Sujirarat, Dusit, Sangprasert, Supha, Sermsuk, Malasod, Sawattrakool, Namthip, & Woskie, Susan Renee, “Glyphosate and Paraquat in Maternal and Fetal Serums in Thai Women,” Journal of Agromedicine, 2017, 22(3), 282-289. DOI: 10.1080/1059924x.2017.1319315.


OBJECTIVES: This longitudinal study measured the glyphosate and paraquat concentrations found in maternal and umbilical cord serum in 82 pregnant women who gave birth in three provinces of Thailand.

METHODS: Through questionnaires and biological samples collected at childbirth, factors such as personal characteristics, family members occupation, agricultural activities, and herbicide use in agricultural work were evaluated as predictors of glyphosate and paraquat levels in the pregnant women. Statistical analysis used univariate and binary multiple logistic regression, where the outcome was the probability of exposure to paraquat or glyphosate above the limit of detection associated with occupation and household factors.

RESULTS: The glyphosate concentrations in the pregnant women’s serum at childbirth (median: 17.5, range: 0.2-189.1 ng/mL) were significantly higher (P < .007) than those in the umbilical cord serum (median: 0.2, range: 0.2-94.9 ng/mL). However, the paraquat concentrations in the serum of the pregnant women at childbirth (83% </=limit of detection [LOD], with maximum of 58.3 ng/mL) were similar to those in the umbilical cord serum (80% <LOD, with maximum of 47.6 ng/mL). Women with glyphosate levels >LOD in serum at childbirth were 11.9 times more likely to report work as an agriculturist (P < .001), 3.7 times more likely to live near agricultural areas (P = .006), and 5.9 times more likely to have a family member who worked in agriculture (P < .001). The only factors affecting paraquat exposures in pregnant women at childbirth were reporting the agricultural activity of digging in farm soil and working in the agricultural fields in the third trimester of pregnancy.

CONCLUSIONS: These results show that pregnant women who work in agriculture or live in families that work in agriculture have higher exposures to the herbicides glyphosate and paraquat. The potential for long-term health impacts of these prenatal exposures to children should be evaluated, and greater regulation of the sale and use of herbicides should be considered in Thailand. FULL TEXT