No abstract

Abstract.-The naked marine dinoflagellates Cochlodinium convolutum and C. helicoides are reported for the first time in the Gulf of California. They occurred in seawater at 21-24.5°C. Cochlodinium convolutum was found in both bottle and net samples; its abundance ranged from 400-2200 cells L -1 . A total of 96 specimens of C. convolutum and 23 specimens of C. helicoides were examined from the net phytoplankton samples. A short description is given for each species, and photomicrographs provide information about the main morphological characteristics.

This study was conducted with the objective of determining whether there is a depuration of organochlorine pesticides in breast milk according to breastfeeding time. In total, 171 samples from mothers that lived in the State of Guerrero, Mexico were analyzed. There was a weak negative relationship between pp'DDE (r = -0.216) and Σ-DDT (r = -0.222) concentrations with the days of lactation. In a comparison analysis, a statistically significant decrease of pp'DDT and pp'DDE levels was observed, as well as the Σ-DDT from the first to the fifth week of lactation. A reduction of 0.188 mg/kg lipid of pp'DDE and 0.181 mg/kg lipid of Σ-DDT per week was obtained. HCB, β-HCH and op'DDT concentrations were low and had no major fluctuations between subgroups. The low levels found and the observed reduction in time involve less exposure to the infant to these pollutants. Through this methodology changes in levels of certain organochlorine pesticides in various stages of human milk production may be shown.

El empleo del clembuterol en la producción de ganado implica riesgos a la salud humana que deben ser evaluados y atendidos por las autoridades agropecuarias y sanitarias. En este trabajo se evaluaron los resultados del programa de vigilancia sanitaria de dicho compuesto en productos cárnicos de bovinos que se comercializan en Guerrero, México. Se realizó un análisis retrospectivo del periodo comprendido entre 2011 y 2015, sobre la evolución de su uso ilegal y el registro de intoxicaciones alimentarias por clembuterol. Los porcentajes de muestras positivas disminuyeron gradualmente hasta quedar en 2015 en 6.8 % y, en general, fueron más bajos en comparación con los antecedentes inmediatos; sin embargo, siempre fueron superiores a los porcentajes promedio del resto del país (Guerrero= 9.5 %, Nacional= 5.8 %). Las jurisdicciones sanitarias con mayor presencia del fármaco fueron Tierra Caliente y Norte, con 12.1 y 16.8 %, respectivamente, así como en lugares con una población grande como Acapulco (9.6 %). Se reportaron pocos casos de intoxicaciones humanas en los tres primeros años (2011= 3, 2012= 5 y 2013= 4) y ninguno en los dos posteriores; sin embargo hay un sub-registro que puede deberse a diversos factores tanto individuales, regionales e institucionales que se discuten más adelante. El avance observado en este programa ha sido significativo; sin embargo, debe fortalecerse la vigilancia sanitaria con la finalidad de erradicar esta actividad ilegal en el corto plazo.

In Mexico, organochlorine pesticides were used in public health and agriculture programs, causing chronic exposure to the population. Human breast milk samples were collected from 171 mothers who were residents from Guerrero, Mexico. Analysis was carried out by gas chromatography. Median concentrations (mg/kg on fat basis) for the following pesticides were: HCB, 0.009; β-HCH, 0.004; pp'DDE, 0.760; op'DDT, 0.016; pp'DDT, 0.045; and Σ-DDT, 0.833. These values are lower than in other States in Mexico, and in some countries where the use of these pesticides was banned more than 30 years ago. Differences were found in HCB, pp'DDE and pp'DDT concentrations in groups divided according to age (p < 0.05). The older age groups had higher concentrations, except for the comparison between groups 21-23/24-28 years, which were 0.913 and 0.530 mg/kg of pp'DDE, respectively. Given the restrictions on use, a greater decrease in organochlorine pesticide levels in human milk is expected in a few years.