Atmospheric concentrations of PCDD/Fs, dl-PCBs and some pesticides in northern Algeria using passive air sampling

Perfluorooctanesulfonate (PFOS) is the terminal degradation product of many commercially used perfluorinated compounds, and most of the toxicity testing to date has focused on its potential biological effects. While PFOS has been extensively studied, other PFCs including replacement chemicals such as perfluorobutanesulfonate (PFBS) and perfluorobutyric acid (PFBA), have not been well characterized. Despite the relative lack of data available on these other PFCs it has been assumed that they will cause similar or lesser effects than PFOS. This study compared the effects of 10 PFCs routinely found in the environment on mRNA abundance of 7 genes related to processes known to be affected by PFOS, such as fatty acid and cholesterol synthesis, and thyroid development. Rat H4IIE hepatoma cells were exposed and changes in mRNA abundance were quantified by real-time PCR. Significant changes in mRNA abundance were observed. The effects caused by the shorter chain replacement chemicals differed significantly from those caused by PFOS or PFOA. Furthermore, not all of the PFCs caused the same effects, and changes could not simply be attributed to chain-length or functional group. These differences could mean that these replacement chemicals do not act through the same mechanisms as the more studied PFOS and PFOA.     

Chemical characteristics of organic aerosol in Bab-Ezzouar (Algiers). Contribution of bituminous product manufacture

The organic compositions of atmospheric particulate matter from Bab-Ezzouar (Algiers) have been investigated to assess the air pollution levels suspected to be caused by asphalt product and yeast manufactures. After a medium-volume air sampling, soxhlet extraction, alumina elution and HPLC separation, the extracts were analysed by high-resolution gas chromatography (HRGC) and gas chromatography coupled to mass spectrometry (GC-MS). The composition of n-alkane and polycyclic aromatic hydrocarbons (PAH) fractions reflected the petrogenic origin from the emission of asphalt materials production in addition to vascular plant wax emissions. In contrast, microbial activities seemed to play the main role for the presence of n-alkanoic acids at Bab-Ezzouar. The sole nitrated polycyclic aromatic hydrocarbons (NPAH) observed, i.e., 2-nitrofluoranthene (2NFA), was very likely to arise from gas-phase photochemical reaction of parent PAH in the atmosphere. The total aerial levels ranged from 75 to 206 ng m(-3) for n-alkanes, from 153 to 345 ng m(-3) for n-alkanoic acids and from 44 to 100 ng m(-3) for PAH and NPAH. Although the samples were collected during the hot season, the levels of these pollutants seemed to be important and of environmental concern, especially for PAH species.