Taryn Pittfield

Mercury and selenium levels, and selenium:mercury molar ratios of brain, muscle and other tissues in bluefish (Pomatomus saltatrix) from New Jersey, USA.

A number of contaminants affect fish health, including mercury and selenium, and the selenium:mercury molar ratio. Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for consumption of saltwater fish. Yet the relative ameliorating effects of selenium on toxicity within fish have not been examined, nor has the molar ratio in different tissues, (i.e. brain). We examined mercury and selenium levels in brain, kidney, liver, red and white muscle, and skin and scales in bluefish (Pomatomus saltatrix) (n=40) from New Jersey to determine whether there were toxic levels of either metal, and we computed the selenium:mercury molar ratios by tissues. Total mercury averaged 0.32±0.02 ppm wet weight in edible muscle and 0.09±0.01 ppm in brain. Selenium concentration averaged 0.37±0.03 in muscle and 0.36±0.03 ppm in brain. There were significant differences in levels of mercury, selenium, and selenium:mercury molar ratios, among tissues. Mercury and selenium levels were correlated in kidney and skin/scales. Mercury levels were highest in kidney, intermediate in muscle and liver, and lowest in brain and skin/scales; selenium levels were also highest in kidney, intermediate in liver, and were an order of magnitude lower in the white muscle and brain. Mercury levels in muscle, kidney and skin/scales were positively correlated with fish size (length). Selenium levels in muscle, kidney and liver were positively correlated with fish length, but in brain; selenium levels were negatively correlated with fish length. The selenium:mercury molar ratio was negatively correlated with fish length for white muscle, liver, kidney, and brain, particularly for fish over 50 cm in length, suggesting that older fish experience less protective advantages of selenium against mercury toxicity than smaller fish, and that consumers of bluefish similarly receive less advantage from eating larger fish.

Interspecific and intraspecific variation in selenium:mercury molar ratios in saltwater fish from the Aleutians: potential protection on mercury toxicity by selenium.

A number of factors affect the consumption risk from mercury in fish, including mercury levels, seasonal patterns of mercury concentrations, human consumption patterns, and sensitive populations (e.g. pregnant women, fetuses, young children, and yet unknown genetic factors). Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for saltwater fish. We examine levels of mercury and selenium in several species of fish and seabirds from the Aleutians (Alaska), determine selenium:mercury molar ratios, and examine species-specific and individual variation in the ratios as a means of exploring the use of the ratio in risk assessment and risk management. Variation among species was similar for mercury and selenium. There was significant interspecific and intraspecific variation in selenium:mercury molar ratios for fish, and for birds. The mean selenium:mercury molar ratios for all fish and bird species were above 1, meaning there was an excess of selenium relative to mercury. It has been suggested that an excess of selenium confers some protective advantage for salt water fish, although the degree of excess necessary is unclear. The selenium:mercury molar ratio was significantly correlated negatively with total length for most fish species, but not for dolly varden. Some individuals of Pacific cod, yellow irish lord, rock greenling, Pacific halibut, dolly varden, and to a lesser extent, flathead sole, had selenium:mercury ratios below 1. No bird muscle had an excess of mercury (ratio below 1), and only glaucous-winged gull and pigeon guillemot had ratios between 1 and 5. There was a great deal of variation in selenium:mercury molar ratios within fish species, and within bird species, making it difficult and impractical to use these ratios in risk assessment or management, for fish advisories, or for consumers, particularly given the difficulty of interpreting the ratios.

Trusted information sources used during and after Superstorm Sandy: TV and radio were used more often than social media.

Health and safety professionals and the public are interested in the best methods of providing timely information about disasters. The objective of this study was to examine information sources used for Superstorm Sandy with respect to the storm, evacuation routes, shelters, safety, and health issues. Respondents in central New Jersey and Jersey shore communities were differentially impacted by the storm. Jersey shore respondents had higher evacuation rates (47% vs. 13%), higher flood waters in homes, longer power outages (average 23 vs. 6 d), and longer periods without Internet (29 vs. 6 d). Electricity outages disrupted both sources and receivers of communication. Both groups obtained most of their information regarding safety from television, radio, friends, and Web/e-mail. Information sources on health varied by location, with central Jersey respondents using mainly TV and the Web, and Jersey shore respondents obtaining health information from the radio and TV (before the storm). For information on evacuation routes, Jersey shore respondents obtained information from many sources, while central Jersey respondents obtained it from TV. Information on mold was largely obtained from friends and the Web, since mold issues were dealt with several weeks after Sandy. The reliance on traditional sources of information (TV, radio, friends) found in this study suggests that the extreme power outages rendered Web, cell phones, and social media on cell phones less usable, and suggests the need for an integrated communication strategy with redundancies that takes into account prolonged power outages over large geographical areas.

Selenium:mercury molar ratios in freshwater fish from Tennessee: individual, species, and geographical variations have implications for management.

Vertebrates, including humans, can experience adverse effects from mercury consumed in fish. Humans often prefer large predatory fish that bioaccumulate high mercury levels. Recent attention has focused on the role of selenium countering mercury toxicity, but there is little research on the selenium:mercury molar ratios in freshwater fish. We examine selenium:mercury molar ratios in freshwater fish from Tennessee at Poplar Creek which receives ongoing inputs of mercury from the Department of Energy’s Oak Ridge Y-12 facility. Our objective was to determine variation of the ratios within species that might affect the protectiveness of selenium against mercury toxicity. Within species, the ratio was correlated significantly and positively with fish length only for two species. There was great individual variation in the selenium:mercury molar ratio within each species, except striped bass. The lack of a clear relationship between the selenium:mercury molar ratio and fish length, and the intraspecific variation, suggests that it would be difficult to use the molar ratio in predicting either the risk from mercury toxicity or in devising consumption advisories.

Seasonal, locational and size variations in mercury and selenium levels in striped bass (Morone saxatilis) from New Jersey.

We examined total mercury and selenium levels in muscle of striped bass (Morone saxatilis) collected from 2005 to 2008 from coastal New Jersey. Of primary interest was whether there were differences in mercury and selenium levels as a function of size and location, and whether the legal size limits increased the exposure of bass consumers to mercury. We obtained samples mainly from recreational anglers, but also by seine and trawl. For the entire sample (n=178 individual fish), the mean (±standard error) for total mercury was 0.39±0.02 μg/g (=0.39 ppm, wet weight basis) with a maximum of 1.3 μg/g (=1.3 ppm wet weight). Mean selenium level was 0.30±0.01 μg/g (w/w) with a maximum of 0.9 μg/g). Angler-caught fish (n=122) were constrained by legal size limits to exceed 61 cm (24 in.) and averaged 72.6±1.3 cm long; total mercury averaged 0.48±0.021 μg/g and selenium averaged 0.29±0.01 μg/g. For comparable sizes, angler-caught fish had significantly higher mercury levels (0.3 vs 0.21 μg/g) than trawled fish. In both the total and angler-only samples, mercury was strongly correlated with length (Kendall tau=0.37; p<0.0001) and weight (0.38; p<0.0001), but was not correlated with condition or with selenium. In the whole sample and all subsamples, total length yielded the highest r(2) (up to 0.42) of any variable for both mercury and selenium concentrations. Trawled fish from Long Branch in August and Sandy Hook in October were the same size (68.9 vs 70.1cm) and had the same mercury concentrations (0.22 vs 0.21 ppm), but different selenium levels (0.11 vs 0.28 ppm). The seined fish (all from Delaware Bay) had the same mercury concentration as the trawled fish from the Atlantic coast despite being smaller. Angler-caught fish from the North (Sandy Hook) were larger but had significantly lower mercury than fish from the South (mainly Cape May). Selenium levels were high in small fish, low in medium-sized fish, and increased again in larger fish, but overall selenium was correlated with length (tau=0.14; p=0.006) and weight (tau=0.27; p<0.0001). Length-squared contributed significantly to selenium models, reflecting the non-linear relationship. Inter-year differences were explained partly by differences in sizes. The selenium:mercury molar ratio was below 1:1 in 20% of the fish and 25% of the angler-caught fish. Frequent consumption of large striped bass can result in exposure above the EPAs reference dose, a problem particularly for fetal development.

Sushi consumption rates and mercury levels in sushi: ethnic and demographic differences in exposure

There are few papers on sushi consumption and its role in methylmercury exposure. We interviewed 1289 people in a New Jersey university community regarding fish and sushi consumption and collected ‘sushi’ samples for total mercury analysis from New Jersey stores and supermarkets and from New York City, and Chicago. The 92% of interviewees who ate fish, ate an average of 5.06 fish and fish-sushi meals/month; 77% of interviewees reported eating sushi (mean = 3.27 meals/month). Caucasians and Asians ate more sushi meals/month, and more sushi pieces/meal than other ethnicities, with East Asians eating more than South Asians. Some people in all ethnic groups ate more than 40 fish-sushi pieces/ month. Total mercury levels varied significantly by type and quality of sushi, with tuna sashimi having the highest mean levels (0.68 ± 0.05 μg/g = ppm on wet weight basis equivalent to about 0.61 ppm of methylmercury). Tuna roll averaged 0.46 ± 0.09 ppm of total mercury. Other types of sushi averaged less than 0.06 ppm total mercury. Eight interviewees reported eating fish or fish-sushi meals at least daily. We estimated mercury exposure at the 90th percentile of fish-sushi consumption, assuming an average 19.3 g of fish per piece of sashimi grade tuna (averaging 0.608 ppm MeHg), using the USEPA recommended default body mass of 70 kg and the Reference Dose of 0.1 μg/kg/day. The methylmercury intake was estimated at 0.34 μg/kg/day which exceeds the EPA Reference Dose. The top 10% of all ethnic groups exceeded the Reference Dose while Caucasians and Asians exceeded the CDC/ATSDR’s Minimal Risk Level of 0.3 μg/kg/d, as well as the WHO Provisional Tolerable Weekly Intake (1.6 μg/kg). The large tuna such as Bluefin, which are prized for sushi, have the highest mercury levels and are also the most endangered by overfishing. These data suggest that sushi can pose a significant risk from mercury exposure.

Metals in tissues of migrant semipalmated sandpipers (Calidris pusilla) from Delaware Bay, New Jersey.

There is an abundance of field data on levels of metals for feathers in a variety of birds, but relatively few data for tissues, especially for migrant species from one location. In this paper we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in muscle, liver, brain, fat and breast feathers from migrant semipalmated sandpipers (Calidris pusilla) collected from Delaware Bay, New Jersey. Our primary objectives were to (1) examine variation as a function of tissue, (2) determine the relationship of metal levels among tissues, and (3) determine the selenium:mercury molar ratio in different tissues since selenium is thought to protect against mercury toxicity. We were also interested in whether the large physiological changes that occur while shorebirds are on Delaware Bay (e.g. large weight gains in 2-3 weeks) affected metal levels, especially in the brain. There were significant differences among tissues for all metals. The brain had the lowest levels of arsenic and cadmium, and was tied for the lowest levels of all other metals except lead and selenium. Correlations among metals in tissues were varied, with mercury levels being positively correlated for muscle and brain, and for liver and breast feathers. Weights vary among individuals at the Delaware Bay stopover, as they arrive light, and gain weight prior to migration north. Bird weight and levels of arsenic, cadmium, and selenium in the brain were negatively correlated, while they were positively correlated for lead. There was no positive correlation for mercury in the brain as a function of body weight. The selenium:mercury molar ratio varied significantly among tissues, with brain (ratio of 141) and fat having the highest ratios, and liver and breast feathers having the lowest. In all cases, the ratio was above 21, suggesting the potential for amelioration of mercury toxicity.

Heavy metals in fish from the Aleutians: interspecific and locational differences.

The objectives of this study were to examine levels of arsenic, cadmium, lead, mercury and selenium in edible tissue of seven species of marine fish collected from several Aleutian islands (in 2004) to determine: (1) interspecific differences, (2) locational differences (among Aleutian Islands), (3) size-related differences in any metal levels within a species, and (4) potential risk to the fish or to predators on the fish, including humans. We also compared metals levels to those of three other fish species previously examined in detail, as well as examining metals in the edible tissue of octopus (Octopus dofleini). Octopus did not have the highest levels of any metal. There were significant interspecific differences in all metal levels among the fish species, although the differences were less than an order of magnitude, except for arsenic (mean of 19,500 ppb in Flathead sole, Hippoglossoides elassodon). Significant intraisland variation occurred among the four sites on Amchitka, but there was not a consistent pattern. There were significant interisland differences for some metals and species. Mercury levels increased significantly with size for several species; lead increased significantly for only one fish species; and cadmium and selenium decreased significantly with size for halibut (Hippoglossus stenolepis). The Alaskan Department of Health and Social Services supports unrestricted consumption of most Alaskan fish species for all people, including pregnant women. Most mean metal concentrations were well below the levels known to adversely affect the fish themselves, or predators that consume them (including humans), except for mercury in three fish species (mean levels just below 0.3 ppm), and arsenic in two fish species. However, even at low mercury levels, people who consume fish almost daily will exceed guideline values from the Centers for Disease Control and the Environmental Protection Agency.

Effect of Providing Information on Students' Knowledge and Concerns about Hydraulic Fracking.

Governmental agencies, regulators, health professionals, and the public are faced with understanding and responding to new development practices and conditions in their local and regional environment. While hydraulic fracking (fracking) for shale gas has been practiced for over 50 years in some states, it is a relatively recent event in the northeastern United States. Providing environmental health information to the public about fracking requires understanding both the knowledge base and the perceptions of the public. The knowledge, perceptions, and concerns of college students about fracking were examined. Students were interviewed at Rutgers University in New Jersey, a state without any fracking, although fracking occurs in nearby Pennsylvania. Objectives were to determine (1) knowledge about fracking, (2) rating of concerns, (3) trusted information sources, (4) importance of fracking relative to other energy sources, and (5) the effect of a 15-min lecture and discussion on these aspects. On the second survey, students improved on their knowledge (except the components used for fracking), and their ratings changed for some concerns, perceived benefits, and trusted information sources. There was no change in support for further development of natural gas, but support for solar, wind, and wave energy decreased. Data suggest that students’ knowledge and perceptions change with exposure to information, but many of these changes were due to students using the Internet to look up information immediately after the initial survey and lecture. Class discussions indicated a general lack of trust for several information sources available on the Web.

LEAD (Pb) IN BIOTA AND PERCEPTIONS OF Pb EXPOSURE AT A RECENTLY DESIGNATED SUPERFUND BEACH SITE IN NEW JERSEY

The Raritan Bay Slag Site (New Jersey) was designated a Superfund site in 2009 because the seawall, jetties, and sediment contained lead (Pb). Our objective was to compare Pb and mercury (Hg) levels in biota and public perceptions of exposure at the Superfund and reference sites. Samples (algae, invertebrates, fish) were collected from the Raritan Bay Slag Site and reference sites and analyzed for Pb and Hg. Waterfront users were interviewed using a standard questionnaire. Levels of Pb in aquatic organisms were compared to ecological and human health safety standards. Lead levels were related to location, trophic level, and mobility. Lead levels in biota were highest at the western side of the West Jetty. Mean Pb levels were highest for algae (Fucus = 53,600 ± 6990 ng/g = ppb [wet weight], Ulva = 23,900 ± 2430 ppb), intermediate for grass shrimp (7270 ± 1300 ppb, 11,600 ± 3340 ppb), and lowest for fish (Atlantic silversides 218 ± 44 ppb). Within species, Pb levels varied significantly across the sampling sites. Lead levels in algae, sometimes ingested by individuals, were sufficiently high to exceed human safety levels. Mercury levels did not differ between the Superfund and reference sites. Despite the fence and warnings, people (1) used the Superfund and reference sites similarly, (2) had similar fish consumption rates, and (3) were not concerned about Pb, although most individuals knew the metal was present. The fish sampled posed no apparent risk for human consumers, but the algae did.