Occurrence of Cyanazine Compounds in Groundwater:  Degradates More Prevalent Than the Parent Compound

Abstract

A recently developed analytical method using liquid chromatography/mass spectrometry was used to investigate the occurrence of cyanazine and its degradates cyanazine acid (CAC), cyanazine amide (CAM), deethylcyanazine (DEC), and deethylcyanazine acid (DCAC) in groundwater. This research represents some of the earliest data on the occurrence of cyanazine degradates in groundwater. Although cyanazine was infrequently detected in the 64 wells across Iowa sampled in 1999, cyanazine degradates were commonly found during this study. The most frequently detected cyanazine compound was DCAC (32.8%) followed by CAC (29.7%), CAM (17.2%), DEC (3.1%), and cyanazine (3.1%). The frequency of detection for cyanazine or one or more of its degradates (CYTOT) was more than 12-fold over that of cyanazine alone (39.1% for CYTOT versus 3.1% for cyanazine). Of the total measured concentration of cyanazine, only 0.2% was derived from its parent compounds with DCAC (74.1%) and CAC (18.4%) comprising 92.5% of this total. Thus, although DCAC and CAC had similar frequencies of detection, DCAC was generally present in higher concentrations. No concentrations of cyanazine compounds for this study exceeded water-quality criteria for the protection of human health. Only cyanazine, however, has such a criteria established. Nevertheless, because these cyanazine degradates are still chlorinated, they may have similar toxicity as their parent compounds similar to what has been found with the chlorinated degradates of atrazine. Thus, the results of this study documented that data on the degradates for cyanazine are critical for understanding its fate and transport in the hydrologic system. Furthermore, the prevalence of the chlorinated degradates of cyanazine found in groundwater suggests that to accurately determine the overall effect on human health and the environment from cyanazine its degradates should also be considered. In addition, because CYTOT was found in 57.6% of the samples collected from alluvial aquifers, about 2-5 times more frequently than the other major aquifer types (glacial drift, bedrock/karst, bedrock/ nonkarst) under investigation, this finding has long-term implications for the occurrence of CYTOT in streams. It is anticipated that low-level concentrations of CYTOT will continue to be detected in streams for years after the use of cyanazine has terminated (scheduled for the year 2000 in the United States), primarily through its movement from groundwater into streams during base-flow conditions.

Persistence of pharmaceutical compounds and other organic wastewater contaminants in a conventional drinking-water-treatment plant

“…This finding demonstrates the importance of analyzing for degradates in order to understand fully the fate of OWCs in a DWT facility as well as the potential human-health issues associated with chronic exposure to these compounds through drinking water. For other classes of organic compounds, such as pesticides, the importance of analyzing for degradates is well established (Thurman et al, 1994;Kolpin et al, 1997;Kalkhoff et al, 1998;Graham et al, 1999;Kolpin et al, 2001). The absence of many OWCs in finished-water supplies, therefore, does not necessarily imply their complete removal from finished water.…”

National survey of pesticides in groundwater in New Zealand—2002

“…Hence their inclusion in the survey made only a minor difference to the overall pesticide detection rates for this survey. In surveys in the midwestern United States, the inclusion of metabolites of atrazine, alachlor, cyanazine, simazine, dacthal, and DDT significantly increased the pesticide detection rate in groundwater (Kolpin et al 1996(Kolpin et al , 2001. Only DEA and DIA, which can be derived from a number of triazine pesticides, and two DDT metabolites have been included in this study and it is possible that the inclusion of other pesticide metabolites would also increase the detection rates for pesticides in groundwater in New Zealand.…”

Peer Reviewed: When Synthetic Chemicals Degrade in the Environment

“…Specifically, research on pesticides has found degradates in surface water (5)(6)(7)(8)(9)(10), groundwater (11)(12)(13), precipitation (14)(15)(16), air (17,18), and sediment (19,20).…”