Cerdeira Antonio L, dos Santos Neife A G, Pessoa Maria C P Y, Gomes Marco A F, Lanchote Vera L
Embrapa Environment, EMBRAPA, Jaguariúna, São Paulo, Brazil.
J Environ Sci Health B. 2005;40(1):159-65. doi: 10.1081/pfc-200034294.
The region of Ribeirão Preto City, located in Southeast of Brazil, São Paulo State, is an important sugarcane, soybean, and corn producing area with a high level of pesticides utilization. This region is also an important recharge area for groundwater supply of the Guarany aquifer. Since the past ten years atrazine, simazine, ametryn, tebuthiuron, diuron, 2,4-D, picloram, and hexazinone are the main herbicides used in this area. In order to study a possible leaching of some of these herbicides into the aquifer, surface, and groundwater samples were collected in a watershed during the years of 1996 to 2003, from different locations. To detect and quantify the herbicides a GC-MS (gas chromatograph/mass spectrometry) method was used. The response of the herbicides analyzed was linear over the concentration range of 0.02 to 2.0 microg/L. Analysis of groundwater revealed that the herbicides tebuthiuron, diuron, atrazine, simazine, and ametryn were not present in the samples. In the surface water collected in 1997, ametryn was present in two out of nine locations with concentrations ranging from 0.17 and 0.23 microg/L, which is above the allowable 0.1 microg/L according to the European safety level. The leaching potential of tebuthiuron, diuron, atrazine, simazine, 2,4-D, picloram, and hexazinone has been evaluated using CMLS-94, "Chemical Movement in Layered Soil," as simulation model. No leaching into the depth of the water table at 40 m was found.
里贝朗普雷图市位于巴西圣保罗州东南部，是一个重要的甘蔗、大豆和玉米产区，农药使用量很高。该地区也是瓜拉尼含水层地下水供应的重要补给区。在过去十年中，莠去津、西玛津、莠灭净、特丁硫脲、敌草隆、2,4-滴、毒莠定和嗪草酮是该地区主要使用的除草剂。为了研究这些除草剂中的某些是否可能渗入含水层，1996年至2003年期间，在一个流域的不同地点采集了地表水和地下水样本。为了检测和定量除草剂，使用了气相色谱/质谱联用（GC-MS）方法。所分析的除草剂在0.02至2.0微克/升的浓度范围内响应呈线性。对地下水的分析表明，样本中不存在特丁硫脲、敌草隆、莠去津、西玛津和莠灭净等除草剂。在1997年采集的地表水中，九个地点中有两个检测到莠灭净，浓度范围为0.17至0.23微克/升，根据欧洲安全标准，该浓度超过了允许的0.1微克/升。使用CMLS-94“分层土壤中的化学物质迁移”作为模拟模型，对特丁硫脲、敌草隆、莠去津、西玛津、2,4-滴、毒莠定和嗪草酮的淋溶潜力进行了评估。未发现这些除草剂渗入40米深处的地下水位。
