INTRODUÇÃO: A presença de compostos de nitrogênio nos seus diferentes estados de oxidação é indicativo de contaminação do aquífero e de possíveis condições higiênico-sanitárias insatisfatórias. O nitrito e o nitrato estão associados a dois efeitos adversos à saúde: a indução à metemoglobinemia e a formação potencial de nitrosaminas e nitrosamidas carcinogênicas. Assim, foi verificada a contaminação das águas subterrâneas por compostos de nitrogênio, através da determinação de nitrogênio amoniacal, nitrogênio albuminóide, nitrito e nitrato, e avaliada a adequação da legislação vigente. MATERIAL E MÉTODO: Foram analisadas 607 amostras de águas de poços localizadas predominantemente na Região Metropolitana da Grande São Paulo, através de técnicas espectrofotométricas na região do visível. RESULTADOS: Os resultados analíticos foram avaliados com base nas legislações federal e estadual paulista. Das amostras analisadas, 91 (15%) apresentaram teores de pelo menos uma forma do nitrogênio em desacordo com a legislação estadual e 24 (4,0%) apresentaram teores de nitrato em desacordo com a legislação federal. CONCLUSÃO: Apenas o nitrato apresenta valor máximo permissível na legislação federal, enquanto que a estadual contempla os quatro compostos nitrogenados. Com base nos resultados da presença significativa desses derivados nas amostras analisadas, os quais comprometem a qualidade das águas e apresentam riscos potenciais à saúde humana, sugere-se a sua inclusão na legislação federal.

INTRODUCTION: Nitrogen compounds in drinking waters have been related to groundwater contamination and inadequate sanitary conditions. Nitrite and nitrate are etiologic agents of methemoglobinemia. In acid solution, nitrous acid formed from nitrite can react with secondary amines to form carcinogenic nitrosamines. The survey of ammoniacal and albuminoid nitrogen, nitrite and nitrate in groundwater supplies as regards the extent of the contamination they cause and discussion of the drinking water regulation regarding nitrogen compounds. MATERIAL AND METHOD: Samples collected predominantly in the Metropolitan Region of S. Paulo City was analysed for nitrogen compounds using colorimetric methods: N-NH3 and N-albuminoid by the Nessler method, nitrite by diazoted sulfanilamide with N-(1-naphthyl)-ethylenediamine, and nitrate by reaction with phenoldisulphonic acid. RESULTS: Federal and S. Paulo State drinking water regulations, respectively, Portaria 36/90 and Decreto nº 12.486, were applied to interpret the results obtained. Of the 607 samples analysed, 15% of them had at least one of the concentrations of nitrogen compounds exceeding the maximum contaminant level (MCL) of the S. Paulo State Regulation. Otherwise, as regards the Federal Regulation, only 4% of the samples exceeded the MCL requirement for nitrate. CONCLUSION: In federal drinking water regulation only MCL for nitrate is reported. Otherwise, S. Paulo State regulation requirements report MCLs for all the compounds that have been analysed in this work. The observed results showed that concentrations of ammonia and albuminoid nitrogen, and nitrite, as well as nitrate, gave rise to water of inadequate quality, further they may have adverse effects on human health. The inclusion of nitrogen compounds other than nitrate in federal regulation is recommended.

INTRODUÇÃO: A presença de compostos de nitrogênio nos seus diferentes estados de oxidação é indicativo de contaminação do aquífero e de possíveis condições higiênico-sanitárias insatisfatórias. O nitrito e o nitrato estão associados a dois efeitos adversos à saúde: a indução à metemoglobinemia e a formação potencial de nitrosaminas e nitrosamidas carcinogênicas. Assim, foi verificada a contaminação das águas subterrâneas por compostos de nitrogênio, através da determinação de nitrogênio amoniacal, nitrogênio albuminóide, nitrito e nitrato, e avaliada a adequação da legislação vigente. MATERIAL E MÉTODO: Foram analisadas 607 amostras de águas de poços localizadas predominantemente na Região Metropolitana da Grande São Paulo, através de técnicas espectrofotométricas na região do visível. RESULTADOS: Os resultados analíticos foram avaliados com base nas legislações federal e estadual paulista. Das amostras analisadas, 91 (15%) apresentaram teores de pelo menos uma forma do nitrogênio em desacordo com a legislação estadual e 24 (4,0%) apresentaram teores de nitrato em desacordo com a legislação federal. CONCLUSÃO: Apenas o nitrato apresenta valor máximo permissível na legislação federal, enquanto que a estadual contempla os quatro compostos nitrogenados. Com base nos resultados da presença significativa desses derivados nas amostras analisadas, os quais comprometem a qualidade das águas e apresentam riscos potenciais à saúde humana, sugere-se a sua inclusão na legislação federal.

INTRODUCTION: Nitrogen compounds in drinking waters have been related to groundwater contamination and inadequate sanitary conditions. Nitrite and nitrate are etiologic agents of methemoglobinemia. In acid solution, nitrous acid formed from nitrite can react with secondary amines to form carcinogenic nitrosamines. The survey of ammoniacal and albuminoid nitrogen, nitrite and nitrate in groundwater supplies as regards the extent of the contamination they cause and discussion of the drinking water regulation regarding nitrogen compounds. MATERIAL AND METHOD: Samples collected predominantly in the Metropolitan Region of S. Paulo City was analysed for nitrogen compounds using colorimetric methods: N-NH3 and N-albuminoid by the Nessler method, nitrite by diazoted sulfanilamide with N-(1-naphthyl)-ethylenediamine, and nitrate by reaction with phenoldisulphonic acid. RESULTS: Federal and S. Paulo State drinking water regulations, respectively, Portaria 36/90 and Decreto nº 12.486, were applied to interpret the results obtained. Of the 607 samples analysed, 15% of them had at least one of the concentrations of nitrogen compounds exceeding the maximum contaminant level (MCL) of the S. Paulo State Regulation. Otherwise, as regards the Federal Regulation, only 4% of the samples exceeded the MCL requirement for nitrate. CONCLUSION: In federal drinking water regulation only MCL for nitrate is reported. Otherwise, S. Paulo State regulation requirements report MCLs for all the compounds that have been analysed in this work. The observed results showed that concentrations of ammonia and albuminoid nitrogen, and nitrite, as well as nitrate, gave rise to water of inadequate quality, further they may have adverse effects on human health. The inclusion of nitrogen compounds other than nitrate in federal regulation is recommended.

This paper reports a series of data on salinity, current, nutrient and dissolved oxygen concentration observed in the Cananeia-Iguape region. The circulation of the system is dominated by tides entering from Barra de Cananéia and Barra de Icapara. Due to differences in the ebb and flood periods in Mar de Cananéia and Mar do Cubatão, residual flows of opposite directions were observed in the bottom layers of these channels. Observations from January 1982 in Mar de Cananéia showed nutrient concentrations generally higher at high tide than at low tide. The same behaviour was not observed in July 1981, when the concentrations were lower than in January. Differences in nutrient distributions in Mar de Cananeia and Bata de Trapande-Mar do Cubatao are apparently related to local influence of mixing processes, as well as to local biological and chemical processes.

Temporal variation of some physical and chemical observations was performed during four days with six hour of intervals at two fixed stations at the Enseada do Flamengo, Ubatuba, São Paulo. The salinity (34.3‰ - 35.1‰) and temperature values (about 26ºC) are typical of local coastal waters. The dissolved oxygen shows super saturation content with some exceptions. The nitrogen (nitrite and nitrate) forms have very low values, with a maximum of 1.0 µg-at/l (nitrate). Other nutrients, like phosphates (0.15 - 0.80 µg-at/l) and silicates (5.0-21.5 µg-at/l) and the relationship N:P (1:3)3 show the poor terrigenous contribution and small bioproductivity. The pH and alcalinity was normal for sea water.