As the United States, Canada, and Mexico prepare for next month’s North American Free Trade Agreement negotiations, several environmental and labor groups have slammed the agreement, calling for an overhaul of NAFTA priorities.

However, many environmental groups continue to attack the trade agreement. Environmental groups claim that NAFTA has contributed to pollution in member countries. Meanwhile, union groups reject NAFTA, claiming the agreement has depressed wages.

In a set of recommendations released last month, the AFL-CIO claimed that “[NAFTA] has failed working people in Canada, Mexico and the United States.” The AFL-CIO went on to claim that NAFTA has led to stagnating wages in all three countries, and relaxed environmental protection standards.

The benefits of free trade are well documented. Expanded trade through NAFTA has contributed to the expansion of all three participating economies.

But misguided criticisms of NAFTA aren’t new from some liberal groups that oppose the liberalization of trade.

Back in 2014, the Sierra Club and other environmental groups released a report charging NAFTA with “higher levels of air and water pollution” and “the progressive weakening of environmental safeguards” in Mexico. In the past, the group has accused NAFTA of, among other things, decreasing wages in Mexico.

However, the data show Mexico has benefitted greatly from NAFTA, while preserving the environment and improving wages for Mexican workers. Despite claims that NAFTA has caused increased pollution in Mexico, over 96 percent of Mexicans now have access to clean water, compared to 85 percent when NAFTA took effect in 1994.

The people of Mexico have also seen great improvements in sanitation. Today, over 85 percent of its citizens have access to improved sanitation facilities, compared to less than 70 percent when NAFTA was enacted.

The United States, Mexico, and Canada all score better on Yale University’s Environmental Performance Index than they did 10 years ago.

Union groups’ claims that NAFTA has caused stagnant, or even decreasing, wages in Mexico are equally questionable.

Since 2000, wages in Mexico have increased over 7 percent after adjusting for inflation, while real wages in the United States and Canada have increased 16 percent and 24 percent, respectively.

So despite accusations that NAFTA has hurt working people and the environment, the data show improvements across the board. On average, working people across Mexico, Canada, and the United States now make more money, and live in cleaner, healthier environments than they did before NAFTA.