評論
打印
Next, we'll take a look at the most recent reports published by local water works
下面我們來看地方供水系統發布的最新的報告
and see what level of nitrates exist in your drinking water.
來分析一下日常飲用水中含有多少硝酸鹽
These two charts sum up the most recent data for nitrate levels in drinking water in De Moines and Aimes.
這兩個表格總結了關于De Moines和Aimes的飲用水中硝酸鹽的含量的最新情況，
The number highlighted in yellow
黃色標記的數字是兩個城市的
is the amount of nitrate detected as reported by each city's public works department.
公共工作部門檢測到的硝酸鹽的含量
De Moines Water Works or DMWW obtains water from the Raccoon River and ground water under the influence of it.
De Moines自來水，簡稱為DMWW，它的水源來自于河水和地下水，其中地下水又受河水影響據水利部門，
A challenge according to the Water Works is that
水利部門的一項挑戰就是
the Raccoon River has the highest average nitrate concentration of any of the 42 largest tributaries in the Mississippi River Basin.
這條河的河水中硝酸鹽的含量是密西西比河灣處42條支流中最高的
De Moines Water Works removes nitrates from the water by operating its nitrate removal facility,
水利部門通過硝酸鹽處理裝置將水中的硝酸鹽析出
the largest of its kind in the world.
這個裝置是世界上同類裝置中規模最大的
This keeps nitrate, nitrogen levels below 10 milligrams per liter, the EPA limit for safe water.
這就使硝酸鹽和氮減少到每升10毫克一下，從而符合環保局的安全標準
Aimes water comes from 22 ground water wells drawing from the Aimes Aquifer.
Aimes的飲用水來自于地下蓄水層打出的22眼地表水井，
Aquifers are pockets of water deep underground that
地下蓄水層
have the benefit of different types of filtration before the water is extracted.
存儲著深層地下水，在被打上來之前需要進行一系列的過濾處理
The benefits of such a system are demonstrable
這樣一個系統的優勢顯而易見
considering the differences in measured nitrate levels in De Moines at 5 to 9 milligrams per liter
在De Moines水中的硝酸鹽含量為每升5-9毫克，
and at Aimes at less than 0.10 milligrams per liter.
而在Aimes這一數值小于每升0.10毫克
Measurements can also indicate levels of microbial contamination
這些措施還能表明微生物的污染水平，
which leads to our next discussion of microbial safety of organic foods versus conventional foods.
這就會引出我們要討論的下一個話題，那就是有機食品和傳統食品中微生物污染哪個更高，
In summary, nitrite and nitrates can be hazardous to very young children by forming methmoglobin,
總而言之，硝酸鹽和亞硝酸鹽能夠通過產生有害物質從而威脅兒童的生長，
which prevents the blood from carrying sufficient oxygen
因為這種物質能夠減少血液中的含氧量，
but are not known to have negative health effects to adults
但是它對成人的身體健康卻不會產生負面影響
until extreme levels of 10 milligrams per liter are reached
除非含量達到每升10毫克，
since the acidic environment of the adult stomach stops the break down of nitrate to nitrite at levels below the maximum.
因為成人胃中的酸性環境能夠有效阻止硝酸鹽變為亞硝酸鹽
Nitrites and nitrates are monitored and controlled by current USDA practices for both conventional and organic food.
傳統食品和有機食品中的亞硝酸鹽和硝酸鹽含量都由農業部進行監控
E-coli is a naturally occurring bacteria found in the intestinal tract of warm-blooded organisms.
大腸桿菌是生長在溫血動物大腸中的常見細菌
Kept within the confines of an animal or human's intestinal tract, E-coli is harmless.
在腸道中的大腸桿菌對人和動物都是無害的，
However, if E-coli reaches uncooked or un-cleaned food through bad food safety practices or fecal contamination,
但是如果大腸桿菌通過不正規的處理方式或者糞便到達了生的，或者沒有洗凈的食物上
it can cause severe food poisoning and even death to humans.
那么就會造成嚴重的食物中毒甚至導致死亡，
In 2002, 2003, and 2004, researchers from the University of Minnesota undertook an extensive study
從2002-2004年明尼蘇達大學的研究人員展開了深入研究，
to compare rates of E-coli contamination from use of animal manure in crop preparation on farms in Minnesota and Wisconsin.
對比明尼蘇達州和威斯康辛州由于使用糞肥使植物沾染大腸桿菌的情況
The researchers asked farmers to complete a questionnaire that
研究人員讓當地農民填寫調查問卷，
covered farm practices with a focus on application standards of animal manure based on composting time greater or less than six months.
問卷中包括了一些與耕作習慣有關的問題，重點關注糞肥的使用是否符合標準，即堆肥的制作過程是否超過六個月
Participating farmers were visited two to three times during the test period.
在測試期間，研究人員會到參與調查的農民家中拜訪兩至三次，
Samples of fruits and vegetables were collected directly from the farm fields
水果和蔬菜樣本都是直接從農場中采摘的，
and without any washing or rubbing off of soil particles were transferred into sterile,
沒有對表面的土壤和灰塵進行任何處理，直接裝入密封的專用袋中，
Zip-lock bags Gloves and knives used were sanitized with alcohol swabs between collections to prevent cross-contamination.
采摘過程中用到的刀子和手套等每次都要經過酒精消毒以防交叉感染
