Aqueous-Phase Photochemical Formation of Peroxyl Radicals and Singlet Molecular Oxygen in Cloud Water Samples from Across the United States

Enteric viruses (EV) are the largest contributors to foodborne illness and outbreaks globally. Their ability to persist in the environment, coupled with the challenges experienced in environmental monitoring create a critical aperture through which agricultural crops may become contaminated. This study involved a seventeen-month investigation of select human enteric viruses and viral indicators in non-traditional irrigation water sources, surface and reclaimed waters, in the Mid-Atlantic region of the United States. Real-time quantitative PCR was used for detection of Aichi virus, hepatitis A virus, noroviruses GI and GII. Pepper mild mottle virus (PMMoV), a common viral indicator of human fecal contamination, was also evaluated along with atmospheric (air and water temperature, cloud cover, and precipitation 24 h, 7 d and 14 d prior to sample collection) and physicochemical (dissolved oxygen, pH, salinity and turbidity) data to determine if there were any association between EV and measured parameters. EV were detected more frequently in reclaimed waters (32%, n=22) than in surface waters (4%, n=49) similar to PMMoV detection frequency in surface (33%, n=42) and reclaimed (67%, n=21) water. Our data show a significant correlation between EV and PMMoV (R2=0.628; p<0.05) detection in reclaimed water samples, but not in surface waters (R2=0.476; p=0.78). Water salinity significantly affected the detection of both EV and PMMoV (p<0.05) as demonstrated by logistic regression analyses. These results provide relevant insights into the extent and degree of association between human enteric (pathogenic) viruses and water quality data in Mid-Atlantic surface and reclaimed waters as potential sources for agricultural irrigation. IMPORTANCE Microbiological analysis of agricultural waters is fundamental to ensure microbial food safety. The highly variable nature of non-traditional sources of irrigation water are particularly difficult to test for the presence of viruses. Multiple characteristics influence viral persistence in a water source as well as affect the recovery and detection methods which are employed. Testing for a suite of viruses in water samples is often too costly and labor intensive, making identification of suitable indicators for viral pathogen contamination necessary. The results from this study address two critical data gaps: enteric virus prevalence in surface and reclaimed waters of the Mid-Atlantic region of the United States and subsequent evaluation of physicochemical and atmospheric parameters used to inform the potential for use of indicators of viral contamination.

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Emissions and photochemistry of oxygenated VOCs in urban plumes in the Northeastern United States

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-7081-2011 ◽

2011 ◽

Vol 11 (14) ◽

pp. 7081-7096 ◽

Cited By ~ 28

Author(s):

R. Sommariva ◽

J. A. de Gouw ◽

M. Trainer ◽

E. Atlas ◽

P. D. Goldan ◽

...

Keyword(s):

United States ◽

New York ◽

Acetic Acid ◽

Methyl Ethyl Ketone ◽

The United States ◽

Chemical Mechanism ◽

Methyl Ethyl ◽

Photochemical Formation ◽

Urban Plumes

Abstract. Photochemical processes inside urban plumes in the Northeast of the United States have been studied using a highly detailed chemical model, based upon the Master Chemical Mechanism (MCM). The model results have been compared to measurements of oxygenated VOCs (acetone, methyl ethyl ketone, acetaldehyde, acetic acid and methanol) obtained during several flights of the NOAA WP-3D aircraft, which sampled plumes from the New York City area during the ICARTT campaign in 2004. The agreement between the model and the measurements was within 40–60 % for all species, except acetic acid. The model results have been used to study the formation and photochemical evolution of acetone, methyl ethyl ketone and acetaldehyde. Under the conditions encountered during the ICARTT campaign, acetone is produced from the oxidation of propane (24–28 %) and i-propanol (<15 %) and from a number of products of i-pentane oxidation. Methyl ethyl ketone (MEK) is mostly produced from the oxidation of n-butane (20–30 %) and 3-methylpentane (<40 %). Acetaldehyde is formed from several precursors, mostly small alkenes, >C5 alkanes, propanal and MEK. Ethane and ethanol oxidation account, respectively, for 6–23 % and 5–25 % of acetaldehyde photochemical formation. The results highlight the importance of alkanes for the photochemical production of ketones and the role of hydroperoxides in sustaining their formation far from the emission sources.

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Photochemical characterization of water samples from Minnesota and Vermont sites with malformed frogs: potential influence of photosensitization by singlet molecular oxygen (1O2) and free radicals on aquatic toxicity

Aquatic Toxicology ◽

10.1016/s0166-445x(03)00138-3 ◽

2003 ◽

Vol 65 (3) ◽

pp. 229-241 ◽

Cited By ~ 9

Author(s):

P Bilski ◽

J.G Burkhart ◽

C.F Chignell

Keyword(s):

Free Radicals ◽

Molecular Oxygen ◽

Water Samples ◽

Aquatic Toxicity ◽

Potential Influence ◽

Singlet Molecular Oxygen

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Salmonella Contamination during Production of Cantaloupe: A Binational Study

Journal of Food Protection ◽

10.4315/0362-028x-67.4.713 ◽

2004 ◽

Vol 67 (4) ◽

pp. 713-720 ◽

Cited By ~ 58

Author(s):

A. CASTILLO ◽

I. MERCADO ◽

L. M. LUCIA ◽

Y. MARTÍNEZ-RUIZ ◽

J. PONCE de LEÓN ◽

...

Keyword(s):

United States ◽

Water Samples ◽

Environmental Samples ◽

Rio Grande Valley ◽

The United States ◽

South Texas ◽

Pcr Analysis ◽

E Coli ◽

Binational Study ◽

Valley Area

Six cantaloupe farms and packing plants in South Texas (950 cantaloupe, 140 water, and 45 environmental samples), including the Rio Grande Valley area, and three farms in Colima State, Mexico (300 cantaloupe, 45 water, and 15 environmental samples), were sampled to evaluate cantaloupe contamination with Salmonella and Escherichia coli during production and processing. Samples collected from external surfaces of cantaloupes, water, and the environments of packing sheds on cantaloupe farms were examined for the presence of Salmonella and E. coli. Of a total of 1,735 samples collected, 31 (1.8%) tested positive for Salmonella. Fifteen Salmonella serotypes were isolated from samples collected in Texas, and nine from samples collected in Colima. Two serotypes (Poona and Oranienburg) that have been associated with three large Salmonella outbreaks in the United States and Canada linked to the consumption of contaminated cantaloupe were found in water samples collected at four farms (three from the United States). Susceptibility of Salmonella isolates to 10 antimicrobials was evaluated by disk diffusion. Eighty-eight percent of the isolates from the United States and Mexico were pansusceptible to the antimicrobials tested; eight isolates from the United States demonstrated an intermediate susceptibility to streptomycin and only two isolates were resistant to the same antimicrobial. From Mexico, four isolates showed an intermediate susceptibility to streptomycin and one isolate was resistant to nalidixic acid and streptomycin. Repetitive sequence-based PCR analysis of Salmonella isolates helped to trace potential sources of Salmonella contamination in source water and in subsequent water samples obtained after the filtration systems of U.S. and Mexican cantaloupe farms. No differences could be seen between the levels of Salmonella contamination in melons from both countries.

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Photochemical Formation of Singlet Molecular Oxygen in Illuminated Aqueous Solutions of Several Commercially Available Sunscreen Active Ingredients

Chemical Research in Toxicology ◽

10.1021/tx950197m ◽

1996 ◽

Vol 9 (3) ◽

pp. 605-609 ◽

Cited By ~ 87

Author(s):

John M. Allen ◽

Cynthia J. Gossett ◽

Sandra K. Allen

Keyword(s):

Aqueous Solutions ◽

Molecular Oxygen ◽

Active Ingredients ◽

Singlet Molecular Oxygen ◽

Photochemical Formation

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Atmospheric nitrated phenols at a mountain site in North China: compositions, phase partitioning, and aqueous formation

10.5194/egusphere-egu21-9395 ◽

2021 ◽

Author(s):

Xinfeng Wang ◽

Min Li ◽

Yanan Zhao ◽

Ping Du ◽

Zhiyi Liu ◽

...

Keyword(s):

Gas Phase ◽

Aqueous Phase ◽

Water Samples ◽

High Performance ◽

North China ◽

Pure Water ◽

Cloud Water ◽

Liquid Chromatograph ◽

Phase Partitioning ◽

Total Concentrations

Nitrated phenols in the atmosphere are receiving increasing attentions due to their light absorption and biological toxicity. However, the partitioning characteristics of nitrated phenols among gas, particle, and aqueous phases and the dominant influencing factors remain unclear. In this work, particulate, gaseous, and cloud water samples were simultaneously collected at the summit of Mt. Tai in North China in spring, summer and winter. The contents of 11 nitrated phenols in these samples were determined with an ultra-high-performance liquid chromatograph in tandem with a mass spectrometer. The total concentrations of nitrated phenols in PM2.5 were in the range of several to dozens of ng m-3, a little lower than those measured in gas phase. The total concentrations of nitrated phenols in cloud water were in the level of hundreds of &#181;g L-1. Among the 11 nitrated phenols, 4-nitrophenol and nitrosalicylic acids were the most dominant compounds in PM2.5, while 4-nitrophenol and 2,4-dinitrophenol were the most abundant in gas-phase and cloud water samples. During cloud events, most nitrated phenols were mainly distributed in particle phase, except dinitrophenols which were mainly distributed in gas phase. The observed concentration ratios of aqueous nitrated phenols to those in gas phase were one to two orders higher than the theoretical Henry&#8217;s law coefficients in pure water. Moreover, the measured concentrations of particulate nitrated phenols were substantially greater than the theoretically predicted values. The above results indicate that nitrated phenols potentially formed via aqueous-phase reactions inside the cloud droplets or on the surface of particles. The much higher ratios of the sum of 4-nitrophenol and 5-nitrosalicylic acid to 2,4-dinitrophenol in cloud water than those in PM2.5 further confirms the enhanced formation via aqueous processes. Overall, aqueous-phase reactions were important sources of atmospheric nitrated phenols during cloud events and had significant influences on the abundance and distributions of nitrated phenols in different phases.

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