Telemetry‐based field studies for assessment of acute and short‐term risk to birds from spray applications of chlorpyrifos

Abstract

In a program of avian field studies, radiotelemetry was combined with observations, carcass searches, residue analysis, and determination of brain acetylcholinesterase (AChE) activity to assess the acute and short-term risk posed by chlorpyrifos to birds. Studies were conducted in field crops (brassicas, Poland) and orchards (pome, Italy; citrus, Spain). In total, 25 individual applications of chlorpyrifos were studied on 13 sites. Before each application, birds were fitted with radio transmitters (with minimum stress to birds). Radiotagged birds were monitored and the avifauna observed before, during and for 7 d following each application. A total of 201 birds representing 19 species were radiotagged. In 80% of individual telemetric monitoring periods, birds remained at the study sites. No radiotagged birds showed any sign of intoxication. These included individuals who spent a major proportion of time within treated areas (some individuals located within treated area on >90% of occasions). A total of 7,238 bird sightings were recorded during constant observation during and immediately after application. An additional 4,017 sightings were recorded in 104 individual surveys during 7 d after each application. Two untagged birds (out of 11,255 bird sightings) exhibited atypical behavior for <1 min and 2 to 3 min, respectively, before flying away. This observation (for 0.02% of bird sightings) may or may not have been treatment related. Ten carcasses were recovered (none radiotagged). Residue analysis and brain AChE activity indicated that none was likely to have died from chlorpyrifos exposure. Radiotracking, supported by more traditional assessment methods, was effective for assessing impacts in the field. This extensive field program supports a conclusion that spray applications of chlorpyrifos present a low risk to birds.

Refined Avian Risk Assessment for Chlorpyrifos in the United States

“…All other bird species were predicted to experience little to no mortality. The results for citrus groves indicate that LiquidPARAM might be over-estimating risk to blue grosbeaks (Wolf et al 2010 ).…”

“…Brassica, pome fruit and citrus crops were treated with CPY to determine potential effects on wild birds (Wolf et al 2010 ). Brassica fi elds were located near Sochaczew, Poland, pome fi elds near Belfi ore, northern Italy, and citrus groves in Valencia, Spain.…”

Ecological Risk Assessment for Chlorpyrifos in Terrestrial and Aquatic Systems in the United States

“…Although the results of the LiquidPARAM modeling indicated some acute risk to the most sensitive species for several crops listed on the Lorsban Advanced label (Table 5 ), the evidence from fi eld studies that used the corresponding application rates (i.e., corn, grapefruit, and orange) indicate that fl owable CPY poses little risk to birds (Dittrich and Staedtler 2010 ;Frey et al 1994 ;Gallagher et al 1994 ;Selbach and Wilkens 2008b ;Wolf et al 2010 ). Thus, it would appear that LiquidPARAM Moore et al 201 may be overestimating the risk CPY poses to birds, particularly in those crops with the highest application rates (i.e., grapefruit and orange).…”

Attenuating effects of caffeic acid phenethyl ester with intralipid on hepatotoxicity of chlorpyrifos in the case of rats

“…Organophosphate induced poisonings may occur by inhalation, cutaneous absorption, or ingestion [3]. Inhibition of acetylcholinesterase activity and accumulation of excess acetylcholine at the nerve endings may lead to muscarinic and nicotinic clinical signs [2,4]. Toxic clinical signs induced by OP poisonings may also develop through the occurrence of oxidative stress [5,6].…”