Reply to the EFSA (2016) on the relevance of recent publications (Hofmann et al. 2014, 2016) on environmental risk assessment and management of Bt-maize events (MON810, Bt11 and 1507)

In this commentary, we respond to a report of the EFSA GMO Panel (EFSA EFSA Supp Publ, 1) that criticises the outcomes of two studies published in this journal (Hofmann et al. Environ Sci Eur 26: 24, 2; Environ Sci Eur 28: 14, 3). Both publications relate to the environmental risk assessment and management of Bt-maize, including maize events MON810, Bt11 and maize 1507. The results of Hofmann et al. (Environ Sci Eur 26: 24, 2), using standardised pollen mass filter deposition measurements, indicated that the EFSA Panel model had underestimated pollen deposition and, hence, exposure of non-target organisms to Bt-maize pollen. The results implied a need for safety buffer distances in the kilometre range for protected nature reserve areas instead of the 20–30 m range recommended by the EFSA Panel. As a result, the EFSA Panel revised their model (EFSA EFSA J 13: 4127, 4), adopting the slope of the empirical data from Hofmann et al. The intercept, however, was substantially reduced to less than 1% at one point by introducing further assumptions based on the estimates of mainly panel members, citing possible ‘uncertainty’. Hofmann et al. (Environ Sci Eur 28: 14, 3) published extensive empirical data regarding pollen deposition on leaves. These results were part of a larger 3-year study involving detailed measurements of pollen release, dispersal and deposition over the maize flowering period. The data collected in situ confirmed the previous predictions of Hofmann et al. (Environ Sci Eur 26: 24, 2). Mean levels and observed variability of pollen deposition on maize and four lepidopteran host plants exceeded the assumptions and disagreed with the conclusions of the EFSA Panel. The EFSA Panel reacted in a report (EFSA EFSA Supp Publ, 1) criticising the methods and outcomes of the two published studies of Hofmann et al. while reaffirming their original recommendations. We respond here point-by-point, showing that the critique is not justified. Based on our results on Urtica leaf pollen density, we confirm the need for specific environmental impact assessments for Bt-maize cultivation with respect to protected habitats within isolation buffer distances in the kilometre range.     

Elysia timida (Risso, 1818) (Gastropoda, Opisthobranchia): relationship and feeding deterrence to a potential predator on the south-western Mediterranean coast

The relationship between the sacoglossan Elysia timida and the ornate wrasse Thalassoma pavo was studied in two laboratory experiments using artificial models. A feeding-preference experiment was conducted to determine whether mollusc extract deterred feeding by T. pavo, by using a "realistic" mollusc model (imitating the colour pattern of E. timida) coated with mollusc extract, and a reference model (without imitation or extract), and fishes collected from two locations. It was observed that fish approached, attacked and ate more reference models than mollusc models. A second feeding-preference experiment was designed with four different coloured models: "realistic" (W), green (G), red (R) and chequered (S) pattern. Both fish populations clearly rejected the S model, and differed in their colour preferences. Although both populations seemed to prefer the R and G models equally, the W model was clearly rejected by the fish that coexist with the mollusc at one site (Mazarrón), but was not rejected by the other population of fish which does not coexist with it (Cabo de Palos). Mazarrón fishes would identify the W model with the presence of a toxic compound during their coexistence, and therefore avoid attacking conspicuously coloured E. timida models as a response to their visual signals. Therefore, it was concluded that extract of E. timida is a deterrent for T. pavo, and its effect is sufficiently noxious that the fish tend to avoid it, so that the ability of the fishes to learn to recognise colours and identify certain colour patterns associated with obnoxious prey provides the molluscs the opportunity to survive by exhibiting a conspicuous coloration.     

The toxicity of ammonia,nitrite and nitrate to the fish,Catla catla (Hamilton)

The acute toxicity of unionized ammonia; nitrite and nitrate to the Indian major carp Catla catla (Hamilton) was determined using static and continuous flow through systems for 24 hours. The median lethal concentration (LC50) values for 24 h of ammonia (NH3-N), nitrite (NO2-N) and nitrate (NO3-N) were 0.045 mg/l, 120.84 mg/l and 1565.43 mg/l in static test respectively and were 0.036 mg/l, 117.43 mg/l and 1484.08 mg/l in continuous flow through test respectively.     

Importance of the Japanese anchovy (Engraulis japonicus) to breeding rhinoceros auklets (Cerorhinca monocerata) on Teuri Island, Sea of Japan

Temporal variation in the diet and chick growth of rhinoceros auklets (Cerorhinca monocerata), on Teuri Island, Sea of Japan, was studied to understand how local marine environmental changes affect the reproduction of this piscivorous seabird. The food delivered by parents to chicks was sampled every 1-2 weeks from late May to July, 1994-1998. Overall, the diet of nestling rhinoceros auklets consisted of (by mass) 61% Japanese anchovy (Engraulis japonicus), 18% Japanese sand lance (Ammodytes personatus), 18% Japan Sea greenling (Pleurogrammus azonus), 2% other fish and 1% squid. Among years, the contribution of anchovy ranged from 16% to 93%. Once anchovy occurred in the diet, it dominated (80% on average) thereafter. Accordingly, when anchovy appeared in the diet early in the chick-rearing season (1994, 1998), the contribution of anchovy overall was large. The first appearance of anchovy in the diet of auklets late in the summer of 1997 was possibly related to negatively anomalous sea-surface temperature. Food loads composed of anchovy (34.0 g) were heavier than those of sand lance (22.5 g) and greenling (28.5 g). The energy density of anchovies also was higher: 6.3 kJ g^-1 wet mass compared to 0+ greenling (4.78 kJ g^-1) and 0+ sand lance (3.78 kJ g^-1). Thus, a high proportion of anchovy in the diet resulted in high food load mass, high daily growth rates of chicks and high fledging success. This study highlighted the importance of the time of arrival of migratory high-lipid prey, which is influenced by local oceanographic conditions, to the reproductive performance of a piscivorous seabird.     

Responses of the whipscorpion, Mastigoproctus liochirus (Arachnida, Uropygi) to environmental humidity

Experiments were conducted to determine the responses of third-instar nymphs of the whipscorpion Mastigoproctus liochirus to various moisture (relative humidity) levels under constant temperature conditions, using a linear humidity gradient apparatus. No previous data exist on the water relations of this uropygid. Under saturated conditions (100% RH) animals showed no preference for any section of the chamber. When a humidity gradient was established (20 to 100% RH), whipscorpions exhibited a marked preference for an area of the chamber characterized by 70 to 80% RH.     

Allocation of organic material and energy to the holdfast,stipe, and fronds inPostelsia palmaeformis (Phaeophyta: Laminariales) on the California coast

Postelsia palmaeformis were collected from the lower intertidal at Pigeon Point, California, USA, in May 1987, and the proximate composition and allocation of energy to the various body components were determined. The holdfast and stipe have a proximate composition (% dry weight) of ca. 40% ash, 5.3% protein, 1% lipid, 2% soluble carbohydrate, and 55% insoluble carbohydrate. The fronds have a proximate composition of ca. 25% ash, 6.5% protein, 2% lipid, 3% soluble carbohydrate, and 65% insoluble carbohydrate. The energetic level was ca. 12 kJ g^-1 dry wt and ca. 19 kJ g^-1 ash-free dry wt. The relative proportion of three plant components varied, comprising 26, 39, and 35% wet wt and 20, 42, and 38% kJ for the holdfast, stipe, and fronds, respectively. A plant with a basal stipe diameter of 33 mm contains 114 g wet wt and 266 kJ. The maximal density found in May 1987 was 826 plants, 49 301 g wet wt, and 106 157 kJ m^-2.P. palmaeformis differs in these characteristics from another intertidal pheophyte,Durvillaea antarctica, that is found in a high-energy intertidal zone.     

磺胺甲恶唑对小麦叶片蛋白和叶绿素含量及SOD酶活性的影响

为了探明磺胺甲恶唑(sulfamethoxazole,SMZ)的生态毒理效应,通过实验室人工控制毒理实验,研究了低浓度SMZ暴露对小麦体内超氧化物歧化酶(SOD)活性、叶绿素(CHL)和蛋白质(SP)含量的影响.结果显示:染毒7d后,各浓度组小麦叶片的SOD活性均被显著诱导(P＜0.0l),并且染毒浓度的升高增强了SOD的活性,表明SMZ暴露胁迫下,小麦可启动自身的保护机制以最大限度地减少自由基损伤.而小麦叶片的CHL含量,随着SMZ染毒浓度的增加而逐渐降低.并且当SMZ暴露浓度较高时,小麦叶片的CHL含量被显著抑制(P＜0.05)).当SMZ染毒浓度为0.05～ 0.50 mg· L-1时,SP的含量被显著诱导(P＜ 0.01));1.00 mg·L-1SMZ对SP的含量产生显著(P＜0.01)抑制,这说明SMZ染毒剂量将对蛋白质的合成产生严重影响.综上,SOD的活性变化可反映出SMZ暴露对小麦的污染效应及其生态毒性作用,但将其作为评估SMZ污染暴露的生物标志物有待于进一步深入研究.     

表面活性剂十二烷基苯磺酸钠（SDBS）和十二烷基磺酸钠（SDS）对安氏伪镖水蚤的急性毒性研究(Acute Toxicity of Sodium Dodecyl Benzene Sulfonate（SDBS）and Sodium Dodecyl Sulfate（SDS）to the Copepod, Pseudodiaptomus annandalei)

为探讨表面活性剂成分对海洋桡足类生物的影响,测定了十二烷基苯磺酸钠(SDBS)和十二烷基磺酸钠(SDS)对安氏伪镖水蚤(Pseudo-diaptomus annandalei Sewell)的急性毒性作用.结果表明,SDBS对安氏伪镖水蚤雌体24h、48h、72h和96h的半致死浓度LC50分别为2.40、1.67、1.59和1.58mg·L-1,而对雄体分别为1.84、1.54、1.41和1.40mg·L-1;SDS对雌体24h、48h、72h和96h的LC50分别为54.33、30.85、25.21和15.85mg·L-1,对雄体分别为18.48、13.55、10.51和8.50mg·L-1;SDBS对雌体和雄体的安全浓度分别为0.24mg·L-1和0.32mg·L-1,而SDS对雌体和雄体的分别为2.98mg·L-1和2.19mg·L-1.结果显示,对安氏伪镖水蚤而言,SDBS比SDS的毒性更强;以半致死浓度LC50为参考依据,安氏伪镖水蚤雄体均比雌体对这两种表面活性剂敏感.     

磺胺甲恶唑暴露对小麦叶片蛋白和叶绿素含量及SOD酶活性的影响

为了探明磺胺甲恶唑(sulfamethoxazole,SMZ)的生态毒理效应,通过实验室人工控制毒理实验,研究了低浓度SMZ暴露对小麦体内超氧化物歧化酶(SOD)活性、叶绿素(CHL)和蛋白质(SP)含量的影响。结果显示:染毒7d后,各浓度组小麦叶片的SOD活性均被显著诱导(P<0.01),并且染毒浓度的升高增强了SOD的活性,表明SMZ暴露胁迫下,小麦可启动自身的保护机制以最大限度地减少自由基损伤。而小麦叶片的CHL含量,随着SMZ染毒浓度的增加而逐渐降低。并且当SMZ暴露浓度较高时,小麦叶片的CHL含量被显著抑制(P<0.05))。当SMZ染毒浓度为0.05～0.50mg·L-1时,SP的含量被显著诱导(P<0.01));1.00mg·L-1SMZ对SP的含量产生显著(P<0.01)抑制,这说明SMZ染毒剂量将对蛋白质的合成产生严重影响。综上,SOD的活性变化可反映出SMZ暴露对小麦的污染效应及其生态毒性作用,但将其作为评估SMZ污染暴露的生物标志物有待于进一步深入研究。     

The effects of KI/Se(VI) molar ratio and initial concentration of Se(VI) on the reduction of Se(VI) to Se(IV) by KI

In this study, potassium iodide (KI) was found to be capable of reducing selenium(VI) to selenium(IV). When KI was added to Se(VI) solution, the Se(VI) concentration rapidly decreased with an increase in the KI/Se(VI) molar ratio. By using the potential-pH equilibrium diagram for the selenium/water system, we confirmed that Se(VI) reduced to Se(IV) because the potential of the solution shifted to the stable Se(IV) region upon the addition of KI. This reduction accompanies the oxidation of I⁻ to I₃⁻. The reduction of Se(VI) by KI was found to be effective for concentrated Se(VI) solutions.     

毒死蜱(CPF)对克氏原螯虾的急性毒性及组织病理观察

采用静水生物测试法研究毒死蜱(CPF)对克氏原螯虾(Procambarus clarkii)的急性毒性效应及克氏原螯虾的组织病变情况并进行安全评价。设定0、2、10、20、40和80μg·L-1 6个CPF浓度梯度进行急性暴露试验,结果表明,CPF浓度升高对克氏原螯虾产生较大毒性,24、48和96 h半致死浓度〔ρ(LC50)〕分别为(28.24±2.81)、(19.50±2.03)和(13.13±1.70)μg·L-1,ρ(LC50)随着暴露时间延长呈显著下降趋势,符合双曲线衰减模型(r=0.999 9,P<0.000 1),安全浓度为(2.79±0.31)μg·L-1。组织病理观察发现,染毒虾心脏上皮细胞增生,心肌肌束间充满血淋巴细胞;神经细胞肿大,尼氏体溶解消失,细胞由多极形状变为圆形,神经纤维坏死并解体;肝胰腺小管收缩并充血,空泡增加;鳃组织空泡化,表面出现黑色素沉积,被多量血淋巴细胞浸润;肌肉纤维萎缩并溶解。     

The iridoid glycoside,catalpol, as a deterrent to the predatorCamponotus floridanus (Formicidae)

Summary We investigated the role of the iridoid glycoside, catalpol, as a deterrent to the predator,Camponotus floridanus. Four laboratory colonies of this ant were offered buckeye caterpillars (Junonia coenia: Nymphalidae) raised on diets with and without catalpol. The same colonies were offered sugar-water solutions containing varying concentrations of catalpol, in both no-choice and choice tests. Regardless of diet, buckeye caterpillars appeared to be morphologically protected from predation by the ants, possibly because of their large spines or tough cuticle. However, buckeyes raised on diets with catalpol had high concentrations of catalpol in their hemolymph; extracts of this high-catalpol hemolymph proved to be an effective deterrent to the ants. When starved ants were not given the choice of food items, they were more likely to consume sucrose solutions that contained 5 mg catalpol/ml or 10 mg catalpol/ml than they were to consume solutions with 20 mg catalpol/ml. When they were given a choice of sugar solution or a sugar solution containing catalpol, the ants avoided solutions with catalpol at any of these concentrations. Ant colony responses to catalpol in sucrose solutions varied considerably over time and among colonies.     

Exposure to metals (Ca,K, Mn) and road salt (NaCl) differentially affect development and survival in two model amphibians

ABSTRACT

Human activity has led to widespread chemical alteration of natural environments. Aquatic ecosystems are especially susceptible to chemical changes, including those caused by runoff and invasive species. Here, we examined the effects of water chemistry, specifically sodium chloride as well as three metals (Ca, K, and Mn) known to differ between native and invasive wetland plant species’ leaf tissues, on the development of two model amphibians: the native Northern leopard frog, Lithobates pipiens, and the non-native African clawed frog, Xenopus laevis. We exposed frog eggs to metal treatment solutions and measured time to hatching (TTH), and following hatching, we exposed tadpoles to a lethal concentration of sodium chloride and recorded time to death (TTD). We found that increasing metal concentrations generally resulted in acceleration of TTH for Xenopus tadpoles, but had no effect on leopard frogs. However, increasing metal concentrations (Ca, Mn) increased leopard frog tadpole susceptibility to NaCl (decreased TTD), while increasing metal concentrations (Ca, K) generally resulted in decreased Xenopus tadpole susceptibility to NaCl. Overall, our data suggest that invasive amphibians may be more tolerant to chemical changes than native amphibians, including those driven by the introduction of invasive plant species.     

不同环境条件下三丁基氧化锡对火腿许水蚤（Schmakeria poplesia）的毒性效应

为探讨不同环境条件下三丁基氧化锡(TBTO)对桡足类的毒性效应,本文通过世代培养30日龄火腿许水蚤(Schmakeria poplesia)的多因素协同作用急性毒性实验,测定了温度、盐度、单胞藻浓度和桡足类密度等环境因素对TBTO毒性效应的影响。结果显示：TBTO对火腿许水蚤雌、雄个体的毒性效应无显著差异,96 h-LC50值分别为 0.41 µgTBTO l-1和0.42 µgTBTO l-1;随着温度的升高,TBTO毒性效应增强;与盐度25条件相比,盐度15和35条件下火腿许水蚤对TBTO的敏感性相对较高;单胞藻浓度升高导致TBTO对桡足类毒性效应降低;另外,桡足类暴露敏感性还受到其密度的影响。以上结果表明,环境因素对污染物的生物毒性效应产生较大影响,在毒理学研究中应根据实际环境情况设定合理的环境条件,以保证最终生态风险评价结果的科学性。     

含铬(Ⅵ)污水对地下水、土壤污染的研究

通过模拟含铬（Ⅵ）污水的土壤淋滤过程，结合受污染区域土壤垂直含铬分布分析，研究了含铬污水渗漏对地下水、土壤的污染。结果表明：含铬污水在亚粘土、亚砂土、砂土中的平均渗透系数分别为６．０２×１０－６ｃｍ／ｓ、３．８７×１０－４ｃｍ／ｓ、５．３２×１０－４ｃｍ／ｓ。含铬污水排放会在土壤中沉积铬，引起土壤污染，并污染地下水。