IMW Initial Phase Report 



and to make the data generally available. We believe that these IMW data will be more fully 

 interpreted over time by comparison with local sets of data in conjunction with Host-Country 

 scientists and that the project has indeed provided a "springboard for action". A summary report to 

 be published in the scientific literature is in preparation. 



The total DDT concentrations (sum of DDD, DDE, and DDT) in the samples from the EMW 

 collection taken along the coast of Central and South America and the Caribbean (Figure 17) are 

 within the range found for the United States coasts during the same sampling period of 1991-1992 

 ( NOAA unpublished data). To provide a nearby direct comparison with the IMW data, the NOAA 

 Status and Trends Stations for the Gulf of Mexico are listed in Table 14. DDT data for these 

 NOAA Status and Trends Mussel Watch Gulf of Mexico stations (Figure 18) can be directly 

 compared to the IMW data subset for the Caribbean area (Figure 19) because GERG was the 

 analytical laboratory for these NOAA S&T samples. All of these data show a similarity for the 

 range of DDT concentrations encountered. 



Beta HCH concentrations are present in the IMW samples at, or below, the limit of 

 detection with the exception of about a dozen samples (Figure 20). In particular, stations ARHU, 

 ARAT, TRCS, BRSB, CHPA, and MEAP deserve attention for elevated concentrations in 

 comparison to other stations. The stations with the higher concentrations of beta HCH in the IMW 

 data set (Figure 20) have concentrations distinctly higher compared to the NOAA Status and 

 Trends Mussel Watch data for the Gulf of Mexico (Figure 21). 



Lindane concentrations are elevated compared to most of the IMW stations for the samples 

 from stations ARHU, ARAT, ARRA, and CHPA (Figure 22). The highest concentrations are 

 above those reported for the NOAA S&T Gulf of Mexico samples but the main portion of the 

 samples have similar concentrations for both the IMW and the NOAA Status and Trends Gulf of 

 Mexico samples (Figures 23). 



Chlordane concentrations are elevated at two stations, ARHU and ARAT compared to a 

 generally low concentration at most IMW stations (Figure 24). The high chlordane concentrations 

 for the three IMW stations are higher than for any of the NOAA Status and Trends concentrations, 

 but the major portion of the concentrations in the IMW data set are similar to concentrations found 

 along the Gulf of Mexico and other U.S. Coasts. (O'Connor, 1991). 



The ARHU and ARAT samples also have chlorobiphenyl concentrations that are 

 significantly elevated compared to the concentrations at other IMW stations (Figure 25). PCB 

 contamination of the Central-South American and Caribbean coasts as indicated in concentrations 

 of selected chlorobiphenyl congeners is similar to that for the United States Gulf of Mexico coast 

 as indicated in comparing the major portion of the data for the IMW data (Figure 25) with the 

 NOAA Status and Trends Mussel Watch Gulf of Mexico data (Figure 26). This is similar to much 

 of the chlorinated pesticide data for which there was general comparability of concentration ranges 



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