Table 6.
Taxon, species | End point | Effect direction | Conc where effect was observed (μg/L) | Conc tested (μg/L) | Atrazine grade | Experiment type | Exposure duration | Reference |
---|---|---|---|---|---|---|---|---|
Testicular cell types | ||||||||
Frog | ||||||||
R. clamitans | Proportion of juvenile males with > 50% tubules containing spermatids and spermatozoa | Lower at agricultural site with highest atrazine concentrations | Range of medians, 0.068–0.78 | ND–3.13a | Comm | FS | Unknown | McDaniel et al. 2008a |
R. pipiens | Proportion of juvenile males with > 50% tubules containing spermatids and spermatozoa | Higher at agricultural site with highest atrazine concentrations | 0.342 (mean of median concentrations) | ND–3.13a | Comm | FS | Unknown | McDaniel et al. 2008a |
Fish | ||||||||
P. promelas | Proportion of primary spermatogonia | ↑ | 25, 250 | 25, 250 | Test | FT | 21 days | U.S. EPA 2005 |
P. promelas | Proportion of secondary spermatogonia | Reduced | 25, 250 | 25, 250 | Test | FT | 21 days | U.S. EPA 2005 |
Sex hormone concentrations | ||||||||
Frog | ||||||||
X. laevis | Testosterone in adult males | ↓ | 25 | 25 | Tech | SR | 46 days | Hayes et al. 2002b |
X. laevis | Testosterone in adult males | ND | – | 10, 100 | Tech | SR | 48 days | Hecker et al. 2005a |
X. laevis | Estradiol in adult males | ND | – | 10, 100 | Tech | SR | 48 days | Hecker et al. 2005a |
X. laevis | Estradiol in adult males | ND | – | 1, 25, 250 | Tech | SR | 36 days | Hecker et al. 2005b |
X. laevis | Testosterone in adult males | ↓ | 250 | 1, 25, 250 | Tech | SR | 36 days | Hecker et al. 2005b |
X. laevis | Testosterone in females | ↓ at agricultural sites, negatively correlated with concentration of atrazine and breakdown product | < 0.1–4.14 | < 0.1–4.14 | Comm | FS | Unknown | Hecker et al. 2004 |
X. laevis | Testosterone in males | Negatively correlated with diamino-chlorotriazine concentration (a product of atrazine breakdown) | < 0.1–4.14 | < 0.1–4.14 | Comm | FS | Unknown | Hecker et al. 2004 |
X. laevis | Estradiol in females | ↓ at agricultural sites, negatively correlated with conc of atrazine and breakdown product | < 0.1–4.14 | < 0.1–4.14 | Comm | FS | Unknown | Hecker et al. 2004 |
R. pipiens | Testosterone in juvenile males (2003) | ↓ at agricultural sites | Range of medians, 0.380–0.780 | ND–3.13a | Comm | FS | Unknown | McDaniel et al. 2008a |
R. pipiens | Testosterone in juvenile males (2003) | Negatively correlated with atrazine concentration | ND–3.13 | ND–3.13a | Comm | FS | Unknown | McDaniel et al. 2008a,c |
R. pipiens | 11-Ketotestosterone in juvenile males (2003) | Negatively correlated with atrazine concentration | ND–3.13 | ND–3.13a | Comm | FS | Unknown | McDaniel et al. 2008a,c |
R. pipiens | Testosterone in adult females (2003) | Negatively correlated with atrazine concentration | ND–3.13 | ND–3.13a | Comm | FS | Unknown | McDaniel et al. 2008a,c |
R. clamitans | 11-Ketotestosterone to testosterone ratio in adult females (late summer Aug–Sep 2002) | ↑ at agricultural sites | Agricultural sites ranged from ND to 250 | ND–250 | Comm | FS | Unknown | Murphy et al. 2006bd |
R. clamitans | 11-Ketotestosterone to testosterone ratio in adult males (late summer Aug–Sep 2002) | ↑ at agricultural sites | Agricultural sites ranged from ND to 250 | ND–250 | Comm | FS | Unknown | Murphy et al. 2006bd |
R. clamitans | 11-Ketotestosterone to testosterone ratio in adult males (early summer May 2003) | ↑ at agricultural sites | Agricultural sites ranged from ND to 0.73 | ND–250 | Comm | FS | Unknown | Murphy et al. 2006bd |
R. clamitans | Estradiol to testosterone ratio in adult females (late summer Aug–Sep 2002) | ↑ at agricultural sites | Agricultural sites ranged from ND to 250 | ND–250 | Comm | FS | Unknown | Murphy et al. 2006bd |
R. clamitans | Estradiol to testosterone ratio in adult males (Late summer Aug–Sep 2002) | ↑ at agricultural sites | Agricultural sites ranged from ND to 250 | ND–250 | Comm | FS | Unknown | Murphy et al. 2006bd |
R. clamitans | Estradiol to testosterone ratio in adult males (early summer May 2003) | ↓ at agricultural sites | Agricultural sites ranged from ND to 0.73 | ND–250 | Comm | FS | Unknown | Murphy et al. 2006bd |
R. clamitans | Estradiol to testosterone ratio in juvenile males (Jul 2003) | ↑ at agricultural sites | Agricultural sites ranged from ND to 0.73 | ND–250 | Comm | FS | Unknown | Murphy et al. 2006bd |
R. clamitans | Testosterone in adult males (early summer May 2003) | ↑ at agricultural sites | Agricultural sites ranged from ND to 0.73 | ND–250 | Comm | FS | Unknown | Murphy et al. 2006bd |
R. clamitans | Testosterone in juvenile females (Jul 2003) | ↑ at agricultural sites | Agricultural sites ranged from ND to 0.73 | ND–250 | Comm | FS | Unknown | Murphy et al. 2006bd |
R. clamitans | Testosterone in juvenile males (Jul 2003) | ↑ at agricultural sitesd | Agricultural sites ranged from ND to 0.73 | ND–250 | Comm | FS | Unknown | Murphy et al. 2006bd |
Fish | ||||||||
P. promelas | Testosterone female | ND | – | 25, 250 | Tech | FT | 21 days | U.S. EPA 2005 |
P. promelas | Estradiol female | Trend (up to a 44% ↓) | 25, 250 | 25, 250 | Tech | FT | 21 days | U.S. EPA 2005e |
P. promelas | Testosterone male | Trend (up to a 31% ↓) | 25, 250 | 25, 250 | Tech | FT | 21 days | U.S. EPA 2005e |
P. promelas | 11-Ketotestosterone male | Trend (up to a 47% ↓) | 25, 250 | 25, 250 | Tech | FT | 21 days | U.S. EPA 2005e |
Reproductive success | ||||||||
Salamander | ||||||||
A. barbouri | Proportion hatched and timing of hatching | ND | – | 4, 40, 400 | Tech | SR | 37 days | Rohr et al. 2003 |
A. barbouri | Proportion hatched and timing of hatching | ↓ and delayed hatching | 400 | 4, 40, 400 | Tech | SR | Mean of 52 days | Rohr et al. 2004 |
Frog | ||||||||
R. pipiens | Proportion hatched | ND | – | 2,590–20,000 | Tech | SR | 10 days | Allran and Karasov 2001 |
R. clamitans | Proportion hatched | ND | – | 2,590–20,001 | Tech | SR | 10 days | Allran and Karasov 2001 |
B. americanus | Proportion hatched | ND | – | 2,590–20,002 | Tech | SR | 10 days | Allran and Karasov 2001 |
Fish | ||||||||
P. promelas | Eggs per spawning of exposed adults | Trend for a ↓ | 5 | 5, 50 | Tech | SR | 21 days | Bringolf et al. 2004b |
P. promelas | Number of spawnings of exposed adults | Trend for a ↓ | 50 | 5, 50 | Tech | SR | 21 days | Bringolf et al. 2004b |
P. promelas | Fertilization success of exposed adults | Trend for a ↓ | 50 | 5, 50 | Tech | SR | 21 days | Bringolf et al. 2004b |
P. promelas | Proportion hatched and larval development of offspring from exposed adults | ND | – | 5, 50 | Tech | SR | 21 days | Bringolf et al. 2004b |
P. promelas | Egg production of exposed adults | ND | – | 25, 250 | Tech | FT | 21 days | U.S. EPA 2005 |
P. promelas | Fertilization success of exposed adults | ND | – | 25, 250 | Tech | FT | 21 days | U.S. EPA 2005 |
P. promelas | Proportion hatched and larval development of offspring from exposed adults | ND | – | 25, 250 | Tech | FT | 21 days | U.S. EPA 2005 |
Abbreviations: ↓, decreased; ↑, increased; Comm, commercial; Conc, concentration; FS, field survey; FT, flow-through experiment; ND, not detected; SR, static renewal experiment, Tech, technical. Excluded studies are listed in Supplemental Material, Table S1 (doi:10.1289/ehp.0901164.S1).
Atrazine concentration for the nonagricultural reference site during 2003 was reported incorrectly; repeated attempts to contact the authors for clarification have not been forthcoming.
No test statistics or degrees of freedom were presented; however, means and variances were presented either in the text or in a figure of the article.
Authors reported no significant correlation between atrazine and sex hormones in their abstract when, in fact, these end points were negatively correlated; contrary to the authors’ conclusion, the negative correlations across sexes and age groups reported in their study are unlikely to occur because of a low sample size or sampling error.
Authors argued that differences in hormone levels between agricultural and nonagricultural sites cannot be due to atrazine because hormone concentrations do not correlate with atrazine concentration; however, they presented no statistics to support this claim.
Low samples sizes (7–8 fish) likely precluded detecting these considerable effects.