Correlations in the chemical composition of rural background atmospheric aerosol in the UK determined in real time using time-of-flight mass spectrometry

An aerosol time-of-flight mass spectrometer (ATOFMS) was used to determine, in real time, the size and chemical composition of individual particles in the atmosphere at the remote inland site of Eskdalemuir, Scotland. A total of 51,980 particles, in the size range 0.3-7.4 microm, were detected between the 25th and 30th June 2001. Rapid changes in the number density, size and chemical composition of the atmospheric aerosol were observed. These changes are attributed to two distinct types of air mass; a polluted air mass that had passed over the British mainland before reaching Eskdalemuir, interposed between two cleaner air masses that had arrived directly from the sea. Such changes in the background aerosol could clearly be very important to studies of urban aerosols and attempts at source apportionment. The results of an objective method of data analysis are presented. Correlations were sought between the occurrence of: lithium, potassium, rubidium, caesium, beryllium, strontium, barium, ammonium, amines, nitrate, nitrite, boron, mercury, sulfate, phosphate, fluorine, chlorine, bromine, iodine and carbon (both elemental and organic hydrocarbon) in both fine (d < 2.5 microm) and coarse (d > 2.5 microm) particle fractions. Several previously unreported correlations were observed, for instance between the elements lithium, beryllium and boron. The results suggest that about 2 in 3 of all fine particles (by number rather than by mass), and 1 in 2 of all coarse particles containing carbon, consisted of elemental carbon rather than organic hydrocarbon (although a bias in the sensitivity of the ATOFMS could have affected these numbers). The ratio of the number of coarse particles containing nitrate anions to the number of particles containing chloride anions exceeded unity when the air mass had travelled over the British mainland. The analysis also illustrates that an air mass of marine origin that had travelled slowly over agricultural land can accumulate amines and ammonium.     

Variability in the edible fraction content of 60Co, 99Tc, 110mAg, 137Cs and 241Am between individual crabs and lobsters from Sellafield (north eastern Irish Sea)

We investigated the variability of anthropogenic radionuclide content of the edible fractions of individual edible crabs (Cancer pagurus L.) and European lobsters (Homarus gammarus L.) caught commercially in the Sellafield offshore area. Sixteen female and 18 male crabs and 20 female and 17 male lobsters were selected from commercial catches made between 25 May and 5 June 1997. Each gender group was selected to be within the known weight range for commercially caught crustacea from the area. Four artificial radionuclides (60Co, 110mAg, 137Cs or 241Am) were detected by gamma-spectrometry. The edible fraction content of these radionuclides between males and females for either species were not statistically significantly different. 99Tc was analysed by chemical separation and beta-counting. 99Tc concentrations in female crabs tended to be higher (172 +/- 205 (16) Bq kg-1(wet); mean +/- standard deviation (n samples)) than those in males (85 +/- 58 (18) Bq kg-1 (wet)), although this was not a statistically significant difference. For both male and female crabs, 99Tc concentrations tended to decrease with increasing whole live weights. For 99Tc in lobsters the picture is less clear. Female lobsters contained more activity (14800 +/- 7400 (20) Bq kg-1 (wet)) than males (7100 +/- 3900 (17) Bq kg-1 (wet)). The results were used to discuss the implications for sampling and monitoring.     

Prenatal diagnosis of thalidomide syndrome

A case of thalidomide syndrome diagnosed by ultrasound in the 17th week of pregnancy is presented. The pregnant woman had leprosy and received adjuvant treatment with thalidomide. The affected fetus was exposed to the drug until the 35th day of pregnancy and presented absent external ears, upper limb phocomelia and absent tibiae and fibulae. No internal organ abnormalities were noticed at autopsy.     

Effects of lindane on Daphnia magna during chronic exposure

Abstract

Acute and chronic toxicity tests with lindane were conducted on Daphnia magna. The 24‐hr static LC50 was 1.64 mgL^‐1. The sublethal effects of 0.16, 0.25, 0.32, 0.60 and 0.80 mgL^‐1 lindane on the survival, reproduction and growth of D. magna were monitored for 21 days. The algae Nannochloris oculata (5 × 10⁵ cellsmL^‐1) was used to feed the daphnids. The parameters used to determined the effect of the pesticide on D. magna were:mean total young per female, mean brood size, days to first brood, intrinsic rate of natural increase (r), growth, and survival. Reproduction as well as survival was significantly reduced at lindane concentrations of 0.25 mgL^‐1 and higher. The intrinsic rate of natural increase (r) decreased with increasing concentrations of lindane. Growth, as measured by body length, was depressed significantly at 0.25 mgL^‐1 lindane and higher. The chronic data was used to formulate an acute/chronic ratio.     

Evaluation of a Daphnia magna renewal life‐cycle test method with diazinon

Abstract

Acute and chronic toxicity tests with diazinon (diethyl 2‐isopropyl‐6‐methyl‐4‐pyrimidinyl phosphorothionate) were conducted on Daphnia magna. The 24‐hr static LC50 was 0.86 μL.L^‐1. The sublethal effects of 0.05, 0.1, 0.5, 0.75 and 1.0 ngL^‐1 of diazinon concentrations on the survival, reproduction and growth of D. magna were monitored for 21 days. The algae Nannochloris oculata (5 x 10⁵ cellsmL^‐1) was used to feed the daphnids. The parameters used to determined the effect of the pesticide on D. magna were: mean total young per female; mean brood size; days to first brood; intrinsic rate of natural increase (r); growth; and survival. Reproduction as well as survival was significantly reduced at diazinon concentrations of 0.10 ngL^‐1 and higher. The intrinsic rate of natural increase (r) decreased with increasing concentrations of diazinon. Growth, as measured by body length, was depressed significantly at 0.05 ngL^‐1 of diazinon and higher concentrations. The maximum acceptable toxicant concentration (MATC) was calculated. The chronic data was used to formulate an acute/chronic ratio.     

Maternal genetic disorders and fetal development

With improvements in early diagnosis and management of genetic diseases, more women with genetic disorders are reaching reproductive age and becoming pregnant. While pregnancy can have a significant impact on a woman's health when there is an underlying genetic disorder, there can also be fetal effects, including embryopathy, fetal growth restriction, and brain injury. Some maternal genetic disorders are associated with adverse perinatal outcomes, including a high risk of perinatal loss and preterm birth. In this article, we review several maternal genetic disorders associated with fetal risk that are important for clinicians and patients to understand and manage appropriately. These include phenylalanine hydroxylase (PAH) deficiency and other inborn errors of metabolism, tuberous sclerosis complex, myotonic dystrophy, cystic fibrosis, Turner syndrome, sickle cell disease, and connective tissue disorders.     

Lobar holoprosencephaly: prenatal MR diagnosis with postnatal MR correlation

Holoprosencephaly is a congenital anomaly characterized by lack of cleavage of the prosencephalon. Although, relatively rare, it is the most common anomaly that involves both the brain and the face. Prenatal diagnosis of this anomaly using ultrasonography, particularly of the less severe forms, is difficult. Magnetic resonance imaging has recently become an important complement to US in prenatal diagnosis of CNS anomalies. We herein report a patient in whom, at 23 weeks of gestation, US suggested agenesis of the corpus callosum and in whom, at 24 weeks of gestation, MRI correctly diagnosed lobar holoprosencephaly, which was confirmed by a postnatal MRI at 3 weeks of age. Copyright © 2005 John Wiley & Sons, Ltd.