Samuel Atuma

Polybrominated diphenyl ethers in breast milk from Uppsala County, Sweden☆

The breast milk concentrations of polybrominated diphenyl ethers (PBDEs; sum of five congeners: BDE-47, -99, -100, -153, and -154) were determined (by GC-ECD) in samples from 93 primiparous women collected from 1996 to 1999 in Uppsala County, Sweden. Dietary and lifestyle factors were also recorded. The mean PBDE concentration was 4.0 ng/g fat and the distribution of samples was skewed with few high values (maximum 28.2 ng/g fat). BDE-47 was the major congener and constituted 59% of the mean concentration of PBDEs. No significant relationship was found between breast milk concentrations of PBDEs and dietary intake of PBDE, age, body mass index, alcohol consumption, or computer usage. After adjustments for these factors, a weak but significant association between PBDE concentrations and smoking was observed. The dietary intake of PBDE for these women was estimated at 27 ng/day, of which fish contributed almost half. After inclusion of 31 additional samples, collected from 2000 to 2001, time trends were studied. The changes in breast milk PBDE levels between 1996 and 2001, similar to the results from another Swedish study on milk from Stockholm mothers, suggest a peak in PBDE concentrations around 1998 and thereafter decreasing levels. However, far-reaching conclusions about PBDE time trends in milk cannot be drawn from this short study.

Organochlorines and bone mineral density in Swedish men from the general population

Abstract: Persistent organochlorines (POCs), such as polychlorinated biphenyls (PCBs) and DDT, are present at relatively high concentrations in food and show estrogenic, anti-estrogenic or anti-androgenic activity in biological test systems. Because bone mineral density (BMD) in men is influenced by sex hormones, we looked for associations between BMD and serum concentrations of POCs in 115 men (mean age 63 years, range 40–75 years) from the general Swedish population. Ten PCB congeners, five DDT isomers, hexachlorobenzene, three hexachlorocyclohexane isomers, trans-nonachlor and oxychlordane were analyzed by gas chromatography. Quantitative bone measurements were performed by dual-energy X-ray absorptiometry at three sites: whole body, the L2–L4 region of the lumbar spine, and the neck region of the proximal femur, as well as by quantitative ultrasound on the left os calcis (broadband ultrasound attenuation (BUA) and speed of sound (SOS)). After adjustment for confounding factors in linear regression analyses we found no strong association between serum concentrations of single POCs and the five BMD and ultrasound variables. When POCs were grouped according to hormonal activity (estrogenic, anti-estrogenic, anti-androgenic) and the study subjects were divided into organochlorine concentration quartiles, a weak association was indicated between increased serum concentrations of p,p′-DDE (anti-androgenic) and decreased BMD, BUA and SOS. This may suggest that p,p′-DDE could cause negative effects on bone density, but the findings might also be due to chance since multiple comparisons were made in the statistical analysis. Overall our results do not suggest that the studied POCs caused major effects on bone density in our study group.

Survey of consumption fish from swedish waters for chlorinated pesticides and polychlorinated biphenyls

In this survey eighty-seven samples of consumption fish comprising mainly of salmon, pike, eel, herring, whitefish, sea-trout, perch, pike-perch, mackerel, cod, flounder, plaice and sole collected between 1992-1993 have been analysed for the levels of chlorinated pesticides and polychlorinated biphenyls (PCBs). Considering the diversity in the sizes and assortment, locations, and time of catch, the samples are deemed to represent the normal fish variety available to the local people at various seasons of the year. Virtually all the samples contained CB-153 levels below the new established maximum limit of 0.1 mg/kg fresh weight. Results are compared with those obtained between 1985 and 1993. Neither the total PCB (on fat weight basis) nor CB 153 as a marker showed any clear trend for most of the fish species analysed, particularly for the short period 1991-1993. The pesticides, on the other hand, showed a rather good downward trend up till 1991; some of them seem to have virtually attained a steady state after 1991.

CB153 as indicator for congener specific determination of PCBS in diverse fish species from Swedish waters

Abstract Fish samples from various waters in Sweden were analysed for PCB congeners. The results indicated a good correlation between the CB-153 and ΣPCB earlier analysed by using packed column and Chlophen A-50 as standard. Furthermore, the correlation between CB-153 and the sum of seven commonly-analysed CBs (28, 52, 101, 118, 138, 153 and 180), also generally referred to as the regulation-relevant PCB congeners, was also good, with the correlation coefficients ranging between 0.9752 – 0.9998. While CB-153 accounted for about 10% of the total PCB in herring samples, other fish samples analysed show higher percentages of CB-153 (whitefish and sea trout 11%, each, salmon and perch 12% each, eel 13% and char 14%). These data confirm the possibility to use CB-153 as a valuable indicator for total PCB in monitoring programmes.

Separation of PCB congeners using active coal columns

Abstract The affinity of active coal for the planar PCBs has been utilized to effect a structural separation of these congeners from the rest of the PCBs, thereby eliminating potential interferents and improving the quality of analytical data. With two conventional active coal columns, non-ortho, mono-ortho and di-ortho substituted chlorobiphenyls (PCB) in a sample extract, are separated into three distinct fractions. Congener identification, quantification and confirmation are carried out partly by dual-column high resolution GC/ECD, and partly by GC/MS (non-ortho PCB congeners). The method has been applied to herring samples and, among the PCB congeners determined, are IUPAC No 77, 126, 169 (non-ortho PCBs), 118, 105, 156 (mono-ortho PCBs) and 52, 101, 110, 153, 138 and 180 (di-ortho PCBs).

Non-ortho PCB levels in various fish species from the east and west coast of Sweden

Non-ortho (coplanar) PCBs 77, 126 and 169 were determined in a number of fish species from the Swedish coastal environment, using either supercritical fluid extraction (SFE) or the traditional liquid/liquid extraction followed by HPLC separation on porous graphitic carbon (PGC) column prior to GC/MS analysis. While PCB 77 showed the highest concentration level, the TEQ value for PCB 126 was dominant in virtually all the samples analysed. The toxic equivalents, however, indicated some differences in analytical data between 1990 and 1992/93 but these are not significant probably owing to the short period in between.

Toxaphene levels in salmon (Salmo salar) from the Baltic Sea

Three toxaphene congeners have been determined in salmon from the Swedish coastal environment using both supercritical fluid (SFE) and the traditional liquid/liquid extractions. The levels obtained using a modifier-free SFE technique, followed by group separation on a silica gel column, were by far much lower than concentrations obtained by SFE with a modifier or liquid/liquid extraction. The mean concentrations on fresh weight basis using a liquid/liquid extraction technique were 5.87, 8.70 and 1.59 microg/kg for CHBs 26, 50 and 62, respectively. There was a plausible relationship between the various fishing sites and the toxaphene levels.