Bromoxynil is a widely used nitrile herbicide applied to maize and other cereals in many countries. To date, still little is known about bromoxynil turnover and the structural identity of bromoxynil non-extractable residues (NER) which are reported to occur in high amounts. Therefore, we investigated the microbial turnover of ¹³C-labeled bromoxynil for 32 days. A focus was laid on the estimation of biogenic NER based on the turnover of ¹³C into amino acids (AA). At the end, 25% of ¹³C₆-bromoxynil equivalents were mineralized, 2% assigned to extractable residues and 72.5% to NER. Based on 12% in the ¹³C-total AA and an assumed share of AA of 50% in microbial biomass we arrived at 24% of total ¹³C-biogenic NER. About 33% of the total ¹³C-NER could thus be explained by ¹³C-biogenic NER; 67% was unknown and by definition xenobiotic NER with potential for toxicity. The ¹³C label from ¹³C₆-bromoxynil was mainly detected in the humic acids (28.5%), but significant amounts were also found in non-humics (17.6%), fulvic acids (13.2%) and humins (12.7%). The ¹³C-total amino acids hydrolyzed from humic acids, humins and fulvic acids amounted to 5.2%, 6.1% and 1.2% of ¹³C₆-bromoxynil equivalents, respectively, corresponding to total ¹³C-biogenic NER amounts of 10.4%, 12.2% and 2.4%. The humins contained mostly ¹³C-biogenic NER, whereas the humic and fulvic acids may be dominated by the xenobiotic NER. Due to the high proportion of unknown ¹³C-NER and particularly in the humic and fulvic acids, future studies should focus on the detailed characterization of these fractions.

Winnipeg is a city in the Canadian Prairies with a population of about 600,000. Like many other cities and towns in this region of Canada, the city is surrounded by agriculture. Weekly bulk deposition samples were collected from May to September in 2010 and 2011 and analyzed for 43 pesticides used in Prairie agriculture. Fourteen herbicides, five herbicide metabolites, two insecticides, and two fungicides were detected with 98.5 % of the samples containing chemical mixtures. Glyphosate is the most widely used pesticide in Prairie agriculture and accounted for 65 % of the total pesticide deposition over the 2 years. Seasonal glyphosate deposition was more than five times larger in 2011 (182 mm rain) than 2010 (487 mm rain), suggesting increased glyphosate particulate transport in the atmosphere during the drier year. The seasonal deposition of ten other frequently herbicides was significantly positively correlated with the amount of herbicides applied both in and around Winnipeg (r = 0.90, P < 0.001) and with agricultural herbicide use around Winnipeg (r = 0.63, P = 0.05), but not with agricultural herbicide use province wide (P = 0.23). Herbicides 2,4-D (2,4-dichlorophenoxyacetic acid), dicamba, and mecoprop had known urban applications and were more consistently detected in samples relative to bromoxynil and 2-methyl-4-chlorophenoxyacetic acid (MCPA) whose frequency of detections decreased throughout August and September. The Canadian Water Quality Guidelines for irrigation water were frequently exceeded for both dicamba (75 %) and MCPA (49 %) concentrations in rain. None of glyphosate concentrations in rain exceeded any of the Canadian Water Quality Guidelines established for this herbicide.

Wildlife exposures to pest controlling substances have resulted in population declines of many predatory species during the past decades. Many pesticides were subsequently classified as persistent, bioaccumulative, and toxic (PBT) and banned on national or global scales. However, despite their risks for non-target vertebrate wildlife, PBT substances such as anticoagulant rodenticides (ARs) are still permitted for use in Europe and have shown to threaten raptors. Whereas risks of ARs are known, much less information is available on emerging agrochemicals such as currently used PPPs and medicinal products (MPs) in higher trophic level species. We expect that currently used PPPs are relatively mobile (vs. lipophilic) as a consequence of the PBT criteria and thus more likely to be present in aqueous matrices. We therefore analyzed blood of 204 raptor nestlings of three terrestrial (red kite, common buzzard, Montagu’s harrier) and two aquatic species (white-tailed sea eagle, osprey) from Germany. In total, we detected ARs in 22.6% of the red kites and 8.6% of the buzzards, whereas no Montagu’s harriers or aquatic species were exposed prior to sampling. ΣAR concentration tended to be higher in North Rhine-Westphalia (vs. North-Eastern Germany) where population density is higher and intense livestock farming more frequent. Among the 90 targeted and currently used PPPs, we detected six substances from which bromoxynil (14.2%) was most frequent. Especially Montagu’s harrier (31%) and red kites (22.6%) were exposed and concentrations were higher in North Rhine-Westphalia as well. Among seven MPs, we detected ciprofloxacin (3.4%), which indicates that risk mitigation measures may be needed as resistance genes were already detected in wildlife from Germany. Taken together, our study demonstrates that raptors are exposed to various chemicals during an early life stage depending on their sampling location and underpins that red kites are at particular risk for multiple pesticide exposures in Germany.

Passive air samplers were deployed at six locations across the province of Manitoba, Canada, to represent areas with, or at various distances from, agricultural herbicide applications. During the growing seasons in 2008 and 2009, the four southern sites always demonstrated mixtures of current-use herbicides (CUHs) in air, but CUHs were not detected at the two northern sites that were 400 and 800 km away from Manitoba’s most northern boundary of agricultural herbicide applications. The masses of the CUHs detected in the air were most strongly positively associated with their estimated masses typically applied in a ~100-km²township area surrounding the sampling sites (r = 0.70 to 0.74) and to a lesser extent with their estimated mass applied in incrementally larger areas (r = 0.53 to 0.59). The masses of CUHs detected in air were also significantly positively associated with their estimated masses applied at a provincial level (r = 0.45 to 0.52) but not with their reported half-lives in air, suggesting that a system of maintaining records of herbicide use data, even at a coarse scale, can strongly improve agri-environmental risk assessments. Of the nine CUHs detected, MCPA [(4-chloro-2-methylphenoxy)acetic acid] and bromoxynil, which are widely applied in Manitoba agriculture, were the only herbicides detected at all four southern sites. Triallate and metolachlor which have low use in Manitoba were the only CUHs detected in the winter months, confirming that these herbicides are relatively persistent in the air and may undergo long-range transport. Four passive air samplers, each installed 0.5 to 1.5 km apart at the same location, showed variations in the herbicide masses detected with the coefficient of variation ranging from 10 % for bromoxynil in 2008 to 137 % for MCPA in 2009. These variations were particularly observed not only for the two herbicides applied on-site (MCPA and clopyralid) but also for four herbicides transported into the area from longer distances (2,4-D (2,4-dichlorophenoxyacetic acid), bromoxynil, ethalfluralin, and triallate). Future regional-scale research should therefore consider deploying multiple sets of passive air samplers at a site to obtain a more representative measure of herbicide air concentrations.

The contamination of the eggs of farmland birds by currently used plant protection products (PPPs) is poorly documented despite a potential to adversely impact their breeding performance. In this context, 139 eggs of 52 grey partridge Perdix perdix clutches, collected on 12 intensively cultivated farmlands in France in 2010–2011, were analysed. Given the great diversity of PPPs applied on agricultural fields, we used exploratory GC/MS-MS and LC/MS-MS screenings measuring ca. 500 compounds. The limit of quantification was 0.01 mg/kg, a statutory reference. A total of 15 different compounds were detected in 24 clutches. Nine of them have been used by farmers to protect crops against fungi (difenoconazole, tebuconazole, cyproconazole, fenpropidin and prochloraz), insects (lambda-cyhalothrin and thiamethoxam/clothianidin) and weeds (bromoxynil and diflufenican). Some old PPPs were also detected (fipronil(+sulfone), HCH(α,β,δ isomers), diphenylamine, heptachlor(+epoxyde), DDT(Σisomers)), as well as PCBs(153, 180). Concentrations ranged between <0.01 and 0.05 mg/kg but reached 0.067 (thiamethoxam/clothianidin), 0.11 (heptachlor + epoxyde) and 0.34 (fenpropidin) mg/kg in some cases. These results testify an actual exposure of females and/or their eggs to PPPs in operational conditions, as well as to organochlorine pollutants or their residues, banned in France since several years if not several decades, that persistently contaminate the environment.Routes of exposure, probability to detect a contamination in the eggs, and effects on egg/embryo characteristics are discussed with regard to the scientific literature.

An analytical methodology using automatic thermal desorption (ATD) and GC/MS was developed for the determination of 28 pesticides of different chemical classes (dichlobenil, carbofuran, trifluralin, clopyralid, carbaryl, flazasulfuron, mecoprop-P, dicamba, 2,4-MCPA, dichlorprop, 2,4-D, triclopyr, cyprodinil, bromoxynil, fluroxypyr, oxadiazon, myclobutanil, buprofezin, picloram, trinexapac-p-ethyl, ioxynil, diflufenican, tebuconazole, bifenthrin, isoxaben, alphacypermethrin, fenoxaprop and tau-fluvalinate) commonly used in nonagricultural areas in atmospheric samples. This methodology was developed to evaluate the indoor and outdoor atmospheric contamination by nonagricultural pesticides. Pesticides were sampled passive sampling tubes containing Tenax® adsorbent. Since most of these pesticides are polar (clopyralid, mecoprop-P, dicamba, 2,4-MCPA, dichlorprop, 2,4-D, triclopyr, bromoxynil, fluroxypyr, picloram, trinexapac-p-ethyl and ioxynil), a derivatisation step is required. For this purpose, a silylation step using N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide (MtBSTFA) was added before thermal desorption. This agent was chosen since it delivers very specific ions on electronic impact (m/z = M-57). This method was established with special consideration for optimal thermal desorption conditions (desorption temperature, desorb flow and duration; trap heating duration and flow; outlet split), linear ranges, limits of quantification and detection which varied from 0.005 to 10 ng and from 0.001 to 2.5 ng, respectively, for an uncertainty varied from 8 to 30 %. The method was applied in situ to the analysis of passive tubes exposed during herbicide application to an industrial site in east of France.