U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 close



Research
                Research Home
                            National Programs
                            Research Projects
                            Scientific Manuscripts
                            International Engagement
                            Scientific Software/Models
                            Databases and Datasets
                            Office of Scientific Quality Review
            Media
                News & Features
                            Multimedia
                            Briefing Room
                            Down on the Farm
                            Press Room
                            Science in Your Shopping Cart
                            Scientific Discoveries
                            Tellus
                            Under the Microscope
            About ARS
                About ARS Home
                            Staff Directory
                            Labs and Research Centers (Map)
                            Headquarter Offices
                            Organizational Chart
                            Employee Services (REE Employees Only)
                            Office of Outreach, Diversity, and Equal Opportunity
            Work With Us
                Work With Us Home
                            ARS Vacancies at USAJOBS
                            Careers at ARS Information
                            Scientific Collaborations
                            Extramural Agreements
                            1890 Faculty Research Sabbatical ProgramSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            GOEL, A - University Of Marylanditem
                                            McConnell, Lauraitem
                                            TORRENTS, A - University Of Marylanditem
                                            KUANG, Z - University Of Marylanditem
                                            Hapeman, Cathleenitem
                                            MERITT, D - University Of Marylanditem
                                            ALEXANDER, S - University Of Marylanditem
                                            SCUDLARK, J - University Of Delawareitem
                                            SCARBOROUGH, R - State Of Delaware
  Submitted to: Environmental Toxicology and Chemistry
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 3/16/2010
                                    Publication  Date: 5/14/2010
                                    Citation: Goel, A., Mcconnell, L.L., Torrents, A., Kuang, Z., Hapeman, C.J., Meritt, D.W., Alexander, S.T., Scudlark, J.R., Scarborough, R. 2010. Environmental factors affecting the levels of legacy pesticides in the airshed of Delaware and Chesapeake Bays. Environmental Toxicology and Chemistry. 29:1893-1906.Interpretive Summary: Restoration of the Chesapeake Bay, a national treasure and the largest estuary in the United States, is a national priority.  Federal agencies have also recently been tasked with an Executive Order to “use their expertise and resources to contribute significantly to improving the health of the Chesapeake Bay.”  Residues of organic pollutants can cause toxic effects on wildlife many years after they are released.  A number of chlorinated insecticides were banned in the 1960’s through 1980’s due to significant toxicity to aquatic organisms, birds, and humans.  Chlordanes were used for termite control in buildings, p,p’-DDT was used for mosquito control, dieldrin, aldrin, and heptachlor were used in agricultural applications for insect control, and hexachlorocylohexanes (HCH) were used as an insecticide.  One HCH called gamma-HCH or lindane is still in limited use in this country and Canada.  This work represents the first long term study of these legacy pesticides in air and rain in the Chesapeake Bay region.  Air and rain samples were collected over 2000-2003 from three locations on the Upper Delmarva Peninsula.  Overall, the levels were found to be low and slowly declining in the region.  Concentrations in rain were extremely low and were infrequently detected due to the relatively low rain sample volumes collected.  An analysis of the air concentration patterns with temperature and wind speed suggest that while most of the compounds have a significant long range transport source (global background or regional background sources), agricultural soils on the Delmarva may still contain residues of diedrin, heptachlor, and DDE, the degradation product of DDT.  This work suggests that concentrations of these chemicals in soils should be investigated further as potential sources to aquatic and terrestrial organisms in the Chesapeake Bay.
                                Technical Abstract: Weekly air (n=271) and event based rain samples (n=489) collected for the period 2000-2003 from three locations in the Delmarva Peninsula (MD and DE) were utilized to determine levels and temporal trends of legacy pesticides in the atmosphere. The goal was to assess the contribution of atmospheric input of legacy pesticides to the Chesapeake Bay where the water quality and bio-diversity of associated natural areas is on a continued decline. The samples were analyzed for 15 pesticides and degradation products using gas chromatography-mass spectrometry (GC-MS).  Low frequency of detection (<10%) combined with low concentrations reveals that wet deposition is not a significant source of the target analytes to the region. However these chemicals occurred very frequently in gas phase samples (chlordane and hexachlorocyclohexanes were ubiquitous while others were present in <75% of samples) at levels that are consistent with the N-S descending transect (lower than in the Great Lakes) and appear to be decreasing at a faster rate than in the Great Lakes region (half lives < 3 yr for most chemicals).  Levels of one of the most toxic legacy pesticides, p,p’-DDT, were below our method detection limits. The results suggest that levels of these chemicals will decrease more rapidly in the Chesapeake Bay region than in the Great Lakes region.  The atmospheric occurrence is dependent upon the usage patterns, pesticide chemistry and environmental conditions.  Temperature alone did not account for the variability in air concentrations and suggests that long range transport is not the sole source of many of these compounds to the Peninsula. An analysis of enthalpy of phase transfer indicates that dieldrin, heptachlor, and p,p’-DDE (the primary p,p’-DDT degradation product) have local sources in the region.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov